diff --git a/lib/pages/invoice/box_addition.dart b/lib/pages/invoice/box_addition.dart
index 2bf0698..805979f 100644
--- a/lib/pages/invoice/box_addition.dart
+++ b/lib/pages/invoice/box_addition.dart
@@ -45,7 +45,7 @@ class _BoxAdditionState extends State<BoxAddition> {
             onPressed: () => Navigator.of(context).pop(),
           ),
           backgroundColor: primaryColor,
-          title: Text(AppTranslations.of(context).text("box.edit.title")),
+          title: Text(AppTranslations.of(context)!.text("box.edit.title")),
         ),
         body: Card(
           child: Column(
diff --git a/lib/pages/invoice/editor/invoice_carton_table.dart b/lib/pages/invoice/editor/invoice_carton_table.dart
index 8af98b8..6faf7c8 100644
--- a/lib/pages/invoice/editor/invoice_carton_table.dart
+++ b/lib/pages/invoice/editor/invoice_carton_table.dart
@@ -38,7 +38,7 @@ class InvoiceCartonTable extends StatelessWidget {
         ? [Container()]
         : cartons!.asMap().entries.map((p) {
             return Container(
-              color: p.value.isChecked
+              color: p.value.isChecked!
                   ? Colors.grey.withOpacity(0.2)
                   : Colors.grey.shade50.withOpacity(0.2),
               child: Container(
@@ -56,7 +56,7 @@ class InvoiceCartonTable extends StatelessWidget {
                 child: Row(
                   children: <Widget>[
                     onSelect == null
-                        ? p.value.isChecked
+                        ? p.value.isChecked!
                             ? SizedBox(
                                 child: Icon(Icons.check, color: primaryColor),
                                 width: 30)
@@ -72,7 +72,7 @@ class InvoiceCartonTable extends StatelessWidget {
                       crossAxisAlignment: CrossAxisAlignment.start,
                       children: [
                         Text(
-                          p.value.cartonNumber,
+                          p.value.cartonNumber!,
                           style: textStyle,
                         ),
                       ],
diff --git a/lib/pages/invoice/editor/invoice_discount_list.dart b/lib/pages/invoice/editor/invoice_discount_list.dart
index 75a348f..3381a3e 100644
--- a/lib/pages/invoice/editor/invoice_discount_list.dart
+++ b/lib/pages/invoice/editor/invoice_discount_list.dart
@@ -68,7 +68,7 @@ class InvoiceDiscountList extends StatelessWidget {
         onSelectChanged: (value) => Navigator.pop(context, c),
         cells: [
           MyDataCell(new Text(
-            c.code,
+            c.code!,
             style: textStyle,
           )),
           MyDataCell(
diff --git a/lib/pages/invoice/editor/invoice_editor.dart b/lib/pages/invoice/editor/invoice_editor.dart
index 32ddbd3..b40c834 100644
--- a/lib/pages/invoice/editor/invoice_editor.dart
+++ b/lib/pages/invoice/editor/invoice_editor.dart
@@ -91,7 +91,7 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
   _loadCartons() async {
     CartonModel cartonModel = Provider.of<CartonModel>(context, listen: false);
     List<Carton> cartons = await cartonModel.getCartonsForInvoice(
-        widget.fcsShipment!.id, widget.customer!.id);
+        widget.fcsShipment!.id!, widget.customer!.id!);
     cartons.forEach((c) {
       c.isChecked = true;
     });
@@ -104,7 +104,7 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
     ShipmentModel shipmentModel =
         Provider.of<ShipmentModel>(context, listen: false);
     List<Shipment> shipments = await shipmentModel.getShipmentWithHandlingFee(
-        widget.fcsShipment!.id, widget.customer!.id);
+        widget.fcsShipment!.id!, widget.customer!.id!);
     shipments.forEach((s) {
       s.isSelected = true;
     });
@@ -117,7 +117,7 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
   _loadDiscount() async {
     DiscountModel discountModel =
         Provider.of<DiscountModel>(context, listen: false);
-    discounts = await discountModel.getDiscount(widget.customer!.id);
+    discounts = (await discountModel.getDiscount(widget.customer!.id!))!;
     if (discounts != null && discounts.length > 0) {
       setState(() {
         _invoice!.discount = discounts.first;
@@ -281,7 +281,7 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
         Column(
           crossAxisAlignment: CrossAxisAlignment.start,
           children: [
-            Text(dateFormatter.format(_invoice!.invoiceDate)),
+            Text(dateFormatter.format(_invoice!.invoiceDate!)),
             SizedBox(
               height: 10,
             ),
@@ -429,7 +429,7 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
       invoice.cargoTypes = cargoTypes;
       invoice.amount = amount;
       invoice.handlingFee = _invoice!.getHandlingFee();
-      invoice.cartons = _invoice!.cartons.where((c) => c.isChecked).toList();
+      invoice.cartons = _invoice!.cartons.where((c) => c.isChecked!).toList();
       invoice.shipments =
           _invoice!.shipments.where((s) => s.isSelected).toList();
       invoice.discount = _invoice!.discount;
diff --git a/lib/pages/invoice/editor/invoice_handling_fee_list.dart b/lib/pages/invoice/editor/invoice_handling_fee_list.dart
index 8f771c4..5ee937d 100644
--- a/lib/pages/invoice/editor/invoice_handling_fee_list.dart
+++ b/lib/pages/invoice/editor/invoice_handling_fee_list.dart
@@ -72,7 +72,7 @@ class InvoiceHandlingFeeList extends StatelessWidget {
         onSelectChanged: (value) => Navigator.pop(context, c),
         cells: [
           MyDataCell(new Text(
-            c.shipmentNumber,
+            c.shipmentNumber!,
             style: textStyle,
           )),
           MyDataCell(
diff --git a/lib/pages/invoice/invoice_customer_list.dart b/lib/pages/invoice/invoice_customer_list.dart
index 8feee77..3df5226 100644
--- a/lib/pages/invoice/invoice_customer_list.dart
+++ b/lib/pages/invoice/invoice_customer_list.dart
@@ -33,7 +33,7 @@ class _InvoiceCustomerListState extends State<InvoiceCustomerList> {
   _load() async {
     CustomerModel customerModel =
         Provider.of<CustomerModel>(context, listen: false);
-    var users = await customerModel.getInvoiceUsers(widget.fcsShipment!.id);
+    var users = await customerModel.getInvoiceUsers(widget.fcsShipment!.id!);
     setState(() {
       _users = users;
     });
@@ -125,7 +125,7 @@ class _InvoiceCustomerListState extends State<InvoiceCustomerList> {
                             Padding(
                               padding: const EdgeInsets.only(top: 2.0),
                               child: new Text(
-                                customer.name,
+                                customer.name!,
                                 style: new TextStyle(
                                     fontSize: 20.0, color: primaryColor),
                               ),
@@ -133,7 +133,7 @@ class _InvoiceCustomerListState extends State<InvoiceCustomerList> {
                             Padding(
                               padding: const EdgeInsets.only(top: 2.0),
                               child: new Text(
-                                customer.phoneNumber,
+                                customer.phoneNumber!,
                                 style: new TextStyle(
                                     fontSize: 15.0, color: Colors.grey),
                               ),
diff --git a/lib/pages/invoice/invoice_info.dart b/lib/pages/invoice/invoice_info.dart
index e4f8777..ba3adbc 100644
--- a/lib/pages/invoice/invoice_info.dart
+++ b/lib/pages/invoice/invoice_info.dart
@@ -118,7 +118,7 @@ class _InvoiceInfoState extends State<InvoiceInfo> {
         Column(
           crossAxisAlignment: CrossAxisAlignment.start,
           children: [
-            Text(dateFormatter.format(_invoice!.invoiceDate)),
+            Text(dateFormatter.format(_invoice!.invoiceDate!)),
             SizedBox(
               height: 5,
             ),
@@ -140,7 +140,7 @@ class _InvoiceInfoState extends State<InvoiceInfo> {
     );
     final paymentMethodBox = DisplayText(
       labelTextKey: "invoice.payment_method",
-      text: _invoice!.paymentMethod.name,
+      text: _invoice!.paymentMethod!.name,
     );
 
     final cancelBtn = LocalButton(
diff --git a/lib/pages/invoice/invoice_list_row.dart b/lib/pages/invoice/invoice_list_row.dart
index 3009c0d..1ffc7b1 100644
--- a/lib/pages/invoice/invoice_list_row.dart
+++ b/lib/pages/invoice/invoice_list_row.dart
@@ -58,7 +58,7 @@ class InvoiceListRow extends StatelessWidget {
                                 fontSize: 13.0, color: primaryColor),
                           ),
                           new Text(
-                            dateFormatter.format(invoice!.invoiceDate),
+                            dateFormatter.format(invoice!.invoiceDate!),
                             style: new TextStyle(
                                 fontSize: 15.0, color: Colors.grey),
                           )
diff --git a/lib/pages/invoice/invoice_shipment_list_row.dart b/lib/pages/invoice/invoice_shipment_list_row.dart
index 21cf4aa..e77cc75 100644
--- a/lib/pages/invoice/invoice_shipment_list_row.dart
+++ b/lib/pages/invoice/invoice_shipment_list_row.dart
@@ -64,7 +64,7 @@ class _InvoiceShipmentListRowState extends State<InvoiceShipmentListRow> {
                             child: new Text(
                               _fcsShipment.shipmentNumber == null
                                   ? ''
-                                  : _fcsShipment.shipmentNumber,
+                                  : _fcsShipment.shipmentNumber!,
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.black),
                             ),
@@ -72,7 +72,7 @@ class _InvoiceShipmentListRowState extends State<InvoiceShipmentListRow> {
                           Padding(
                             padding: const EdgeInsets.only(left: 10.0, top: 10),
                             child: new Text(
-                              dateFormatter.format(_fcsShipment.cutoffDate),
+                              dateFormatter.format(_fcsShipment.cutoffDate!),
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.grey),
                             ),
@@ -86,7 +86,7 @@ class _InvoiceShipmentListRowState extends State<InvoiceShipmentListRow> {
             ),
             Padding(
               padding: const EdgeInsets.all(0),
-              child: getStatus(_fcsShipment.status),
+              child: getStatus(_fcsShipment.status!),
             ),
           ],
         ),
diff --git a/lib/pages/invoice/invoice_table.dart b/lib/pages/invoice/invoice_table.dart
index c7b1cc7..46ed34b 100644
--- a/lib/pages/invoice/invoice_table.dart
+++ b/lib/pages/invoice/invoice_table.dart
@@ -61,16 +61,16 @@ class InvoiceTable extends StatelessWidget {
   List<InvoiceTableRow> getTableRows() {
     List<InvoiceTableRow> tableRows = [];
     // add cargo types
-    List<CargoType> _cargoTypes = invoice!.getCargoTypes(rate!) ?? [];
+    List<CargoType> _cargoTypes = invoice!.getCargoTypes(rate!);
     _cargoTypes.forEach((c) {
       tableRows.add(InvoiceTableRow(
           invoiceDataType: InvoiceDataType.CargoDataType,
           desc: c.name,
           rate:
-              "${c.calWeight!.toStringAsFixed(2)} x ${c.calRate!.toStringAsFixed(2)}",
+              "${c.calWeight.toStringAsFixed(2)} x ${c.calRate.toStringAsFixed(2)}",
           amount: "${c.calAmount.toStringAsFixed(2)}"));
     });
-    invoice!.shipments.where((ss) => (ss.isSelected ?? false)).forEach((s) {
+    invoice!.shipments.where((ss) => (ss.isSelected )).forEach((s) {
       tableRows.add(InvoiceTableRow(
           data: s,
           invoiceDataType: InvoiceDataType.HandlingFeeType,
@@ -95,7 +95,7 @@ class InvoiceTable extends StatelessWidget {
         invoiceDataType: InvoiceDataType.DeliveryFeeType,
         desc: "Delivery fee",
         rate: "",
-        amount: "${invoice?.deliveryFee?.toStringAsFixed(2) ?? '0'}"));
+        amount: "${invoice?.deliveryFee.toStringAsFixed(2) ?? '0'}"));
 
     // // add discounts
     if (invoice!.discount != null) {
@@ -104,7 +104,7 @@ class InvoiceTable extends StatelessWidget {
           invoiceDataType: InvoiceDataType.DiscountDataType,
           desc: "Discount\n${invoice?.discount?.code ?? ""}",
           rate: "",
-          amount: "(${invoice?.discount?.amount?.toStringAsFixed(2) ?? ''})"));
+          amount: "(${invoice?.discount?.amount.toStringAsFixed(2) ?? ''})"));
     }
 
     return tableRows;
diff --git a/lib/pages/invoice/model/invoice_model.dart b/lib/pages/invoice/model/invoice_model.dart
index f8f7758..2ad13f8 100644
--- a/lib/pages/invoice/model/invoice_model.dart
+++ b/lib/pages/invoice/model/invoice_model.dart
@@ -15,14 +15,14 @@ import 'package:path/path.dart' as Path;
 class InvoiceModel extends BaseModel {
   final log = Logger('InvoiceModel');
 
-  StreamSubscription<QuerySnapshot> listener;
+  StreamSubscription<QuerySnapshot<Map<String, dynamic>>>? listener;
 
   List<Invoice> _invoices = [];
 
   List<Invoice> get invoices =>
       _selectedIndex == 1 ? _invoices : List<Invoice>.from(_paginator.values);
 
-  Paginator _paginator;
+  late Paginator _paginator;
 
   bool endOfPaidInvoices = false;
   bool isLoading = false;
@@ -33,7 +33,7 @@ class InvoiceModel extends BaseModel {
     notifyListeners();
   }
 
-  get selectedIndex => _selectedIndex;
+  int get selectedIndex => _selectedIndex;
 
   @override
   void privilegeChanged() {
@@ -54,11 +54,11 @@ class InvoiceModel extends BaseModel {
     if (user == null) return;
     if (!forCustomer && !user.hasInvoices()) return;
     String path = "/$invoices_collection";
-    if (listener != null) listener.cancel();
+    if (listener != null) listener!.cancel();
     _invoices = [];
 
     try {
-      var q = Firestore.instance
+      var q = FirebaseFirestore.instance
           .collection("$path")
           .where("status", isEqualTo: invoice_issued_status)
           .where("is_deleted", isEqualTo: false);
@@ -69,9 +69,9 @@ class InvoiceModel extends BaseModel {
 
       listener = q.snapshots().listen((QuerySnapshot snapshot) {
         _invoices.clear();
-        _invoices = snapshot.documents.map((documentSnapshot) {
-          var s = Invoice.fromMap(
-              documentSnapshot.data, documentSnapshot.documentID);
+        _invoices = snapshot.docs.map((documentSnapshot) {
+          var s = Invoice.fromMap(documentSnapshot.data as Map<String, dynamic>,
+              documentSnapshot.id);
           return s;
         }).toList();
         notifyListeners();
@@ -85,7 +85,7 @@ class InvoiceModel extends BaseModel {
     if (!isCustomer) {
       if (user == null || !(user.hasInvoices())) throw "No privilege";
     }
-    var pageQuery = Firestore.instance
+    var pageQuery = FirebaseFirestore.instance
         .collection("/$invoices_collection")
         .where("is_deleted", isEqualTo: false);
     if (isCustomer) {
@@ -105,7 +105,7 @@ class InvoiceModel extends BaseModel {
     return paginator;
   }
 
-  Future<void> loadMore({bool isCustomer}) async {
+  Future<void> loadMore({bool? isCustomer}) async {
     if (_paginator.ended || _selectedIndex == 1)
       return; // when paid menu is not selected return
     isLoading = true;
@@ -116,7 +116,7 @@ class InvoiceModel extends BaseModel {
     });
   }
 
-  Future<void> refresh({bool isCustomer}) async {
+  Future<void> refresh({bool? isCustomer}) async {
     if (_selectedIndex == 1) return; // when paid menu is not selected return
     await _paginator.refresh(onFinished: () {
       notifyListeners();
@@ -129,17 +129,17 @@ class InvoiceModel extends BaseModel {
 
   logout() async {
     if (_paginator != null) _paginator.close();
-    if (listener != null) await listener.cancel();
+    if (listener != null) await listener!.cancel();
     _invoices = [];
   }
 
-  Future<Invoice> getInvoice(String id) async {
+  Future<Invoice?> getInvoice(String id) async {
     String path = "/$invoices_collection";
     try {
-      var ref = Firestore.instance.collection("$path").document(id);
-      var snap = await ref.get(source: Source.server);
+      var ref = FirebaseFirestore.instance.collection("$path").doc(id);
+      var snap = await ref.get(const GetOptions(source: Source.server));
       if (snap.exists) {
-        var s = Invoice.fromMap(snap.data, snap.documentID);
+        var s = Invoice.fromMap(snap.data as Map<String, dynamic>, snap.id);
         return s;
       }
     } catch (e) {
diff --git a/lib/pages/invoice/payment/payment_page.dart b/lib/pages/invoice/payment/payment_page.dart
index 641de33..c17e966 100644
--- a/lib/pages/invoice/payment/payment_page.dart
+++ b/lib/pages/invoice/payment/payment_page.dart
@@ -50,9 +50,9 @@ class _PaymentPageState extends State<PaymentPage> {
   _loadInvoice() async {
     InvoiceModel invoiceModel =
         Provider.of<InvoiceModel>(context, listen: false);
-    Invoice i = await invoiceModel.getInvoice(_invoice.id);
+    Invoice? i = await invoiceModel.getInvoice(_invoice.id!);
     setState(() {
-      _invoice = i;
+      _invoice = i!;
     });
   }
 
@@ -97,7 +97,7 @@ class _PaymentPageState extends State<PaymentPage> {
             onPressed: () => Navigator.of(context).pop(),
           ),
           backgroundColor: primaryColor,
-          title: Text(AppTranslations.of(context).text("pm_.title")),
+          title: Text(AppTranslations.of(context)!.text("pm_.title")),
         ),
         body: ListView(
           padding: const EdgeInsets.all(10.0),
@@ -130,74 +130,73 @@ class _PaymentPageState extends State<PaymentPage> {
     List<Widget> dataRow = [];
 
     dataRow = _invoice.payments.map((p) {
-          return Container(
-            decoration: BoxDecoration(
-                border: Border(bottom: BorderSide(color: Colors.grey))),
-            padding: const EdgeInsets.only(
-                left: 5.0, right: 5.0, top: 5.0, bottom: 5.0),
-            child: Row(
-              children: [
-                Expanded(
-                    flex: 1,
+      return Container(
+        decoration: BoxDecoration(
+            border: Border(bottom: BorderSide(color: Colors.grey))),
+        padding:
+            const EdgeInsets.only(left: 5.0, right: 5.0, top: 5.0, bottom: 5.0),
+        child: Row(
+          children: [
+            Expanded(
+                flex: 1,
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Padding(
+                      padding: const EdgeInsets.only(left: 8.0),
+                      child: Text(
+                          '${p.paymentDate != null ? dateFormatter.format(p.paymentDate!) : ""}'),
+                    ),
+                    SizedBox(
+                      height: 5,
+                    ),
+                    LocalImagePicker(
+                      key: ValueKey(p.id),
+                      enabled: false,
+                      initialImgUrl: p.paymentReceiptURL!,
+                      title: "Receipt",
+                      color: primaryColor,
+                    )
+                  ],
+                )),
+            Expanded(
+                flex: 1,
+                child: Center(
                     child: Column(
-                      crossAxisAlignment: CrossAxisAlignment.start,
-                      children: [
-                        Padding(
-                          padding: const EdgeInsets.only(left: 8.0),
-                          child: Text(
-                              '${p.paymentDate != null ? dateFormatter.format(p.paymentDate) : ""}'),
-                        ),
-                        SizedBox(
-                          height: 5,
-                        ),
-                        LocalImagePicker(
-                          key: ValueKey(p.id),
-                          enabled: false,
-                          initialImgUrl: p.paymentReceiptURL,
-                          title: "Receipt",
-                          color: primaryColor,
-                        )
-                      ],
-                    )),
-                Expanded(
+                  children: [Text('\$ ${p.amount}'), Text('${p.status}')],
+                ))),
+            widget.forCustomer!
+                ? Container()
+                : Expanded(
                     flex: 1,
-                    child: Center(
-                        child: Column(
-                      children: [Text('\$ ${p.amount}'), Text('${p.status}')],
-                    ))),
-                widget.forCustomer!
-                    ? Container()
-                    : Expanded(
-                        flex: 1,
-                        child: Row(
-                          mainAxisAlignment: MainAxisAlignment.center,
-                          children: p.status == payment_pending_status
-                              ? [
-                                  InkWell(
-                                    onTap: () => _confirm(p),
-                                    child: Padding(
-                                      padding: const EdgeInsets.all(8.0),
-                                      child: Icon(
-                                        Icons.check,
-                                        color: primaryColor,
-                                      ),
-                                    ),
+                    child: Row(
+                      mainAxisAlignment: MainAxisAlignment.center,
+                      children: p.status == payment_pending_status
+                          ? [
+                              InkWell(
+                                onTap: () => _confirm(p),
+                                child: Padding(
+                                  padding: const EdgeInsets.all(8.0),
+                                  child: Icon(
+                                    Icons.check,
+                                    color: primaryColor,
                                   ),
-                                  InkWell(
-                                    onTap: () => _cancel(p),
-                                    child: Padding(
-                                      padding: const EdgeInsets.all(8.0),
-                                      child: Icon(Icons.close,
-                                          color: primaryColor),
-                                    ),
-                                  ),
-                                ]
-                              : [],
-                        )),
-              ],
-            ),
-          );
-        }).toList() ;
+                                ),
+                              ),
+                              InkWell(
+                                onTap: () => _cancel(p),
+                                child: Padding(
+                                  padding: const EdgeInsets.all(8.0),
+                                  child: Icon(Icons.close, color: primaryColor),
+                                ),
+                              ),
+                            ]
+                          : [],
+                    )),
+          ],
+        ),
+      );
+    }).toList();
 
     dataRow.insert(
         0,
diff --git a/lib/pages/invoice/payment/payment_page_edit.dart b/lib/pages/invoice/payment/payment_page_edit.dart
index 19aa12c..098a354 100644
--- a/lib/pages/invoice/payment/payment_page_edit.dart
+++ b/lib/pages/invoice/payment/payment_page_edit.dart
@@ -154,7 +154,7 @@ class _PaymentPageEditState extends State<PaymentPageEdit> {
             onPressed: () => Navigator.of(context).pop(),
           ),
           backgroundColor: primaryColor,
-          title: Text(AppTranslations.of(context).text("pm_.title")),
+          title: Text(AppTranslations.of(context)!.text("pm_.title")),
         ),
         body: Padding(
           padding: const EdgeInsets.all(8.0),
@@ -189,7 +189,7 @@ class _PaymentPageEditState extends State<PaymentPageEdit> {
         _widget = initialImage();
       } else {
         _widget = InkWell(
-          child: Image.asset(widget.receipt!.fileUrl, fit: BoxFit.cover),
+          child: Image.asset(widget.receipt!.fileUrl!, fit: BoxFit.cover),
           onTap: () {},
         );
       }
diff --git a/lib/pages/market/market_editor.dart b/lib/pages/market/market_editor.dart
index 92f4483..9efdd9e 100644
--- a/lib/pages/market/market_editor.dart
+++ b/lib/pages/market/market_editor.dart
@@ -35,7 +35,7 @@ class _MarketEditorState extends State<MarketEditor> {
         children: <Widget>[
           Expanded(
             child: new Text(
-              p.name,
+              p.name ?? "",
               style: TextStyle(
                 fontSize: 15.0,
               ),
@@ -117,7 +117,7 @@ class _MarketEditorState extends State<MarketEditor> {
     });
     MarketModel marketModel = Provider.of<MarketModel>(context, listen: false);
     try {
-      await marketModel.deleteMarket(market.id);
+      await marketModel.deleteMarket(market.id!);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
     } finally {
diff --git a/lib/pages/market/model/market_model.dart b/lib/pages/market/model/market_model.dart
index c97cbdb..7f45b50 100644
--- a/lib/pages/market/model/market_model.dart
+++ b/lib/pages/market/model/market_model.dart
@@ -20,14 +20,14 @@ class MarketModel extends BaseModel {
     try {
       if (listener != null) listener.cancel();
 
-      listener = Firestore.instance
+      listener = FirebaseFirestore.instance
           .collection("/$config_collection/$setting_doc_id/$markets_collection")
           .snapshots()
           .listen((QuerySnapshot snapshot) {
         markets.clear();
-        markets = snapshot.documents.map((documentSnapshot) {
+        markets = snapshot.docs.map((documentSnapshot) {
           var user = Market.fromMap(
-              documentSnapshot.data, documentSnapshot.documentID);
+              documentSnapshot.data as Map<String, dynamic>, documentSnapshot.id);
           return user;
         }).toList();
         notifyListeners();
diff --git a/lib/pages/package/model/package_model.dart b/lib/pages/package/model/package_model.dart
index f826ceb..0b53d77 100644
--- a/lib/pages/package/model/package_model.dart
+++ b/lib/pages/package/model/package_model.dart
@@ -16,9 +16,9 @@ import 'package:path/path.dart' as Path;
 class PackageModel extends BaseModel {
   final log = Logger('PackageModel');
 
-  PaginatorListener packages;
-  PaginatorListener customerPackages;
-  PaginatorListener activePackages;
+  PaginatorListener? packages;
+  PaginatorListener? customerPackages;
+  PaginatorListener? activePackages;
 
   bool isLoading = false;
   int _menuSelectedIndex = 1;
@@ -32,7 +32,7 @@ class PackageModel extends BaseModel {
     notifyListeners();
   }
 
-  get menuSelectedIndex => _menuSelectedIndex;
+  int get menuSelectedIndex => _menuSelectedIndex;
 
   void privilegeChanged() {
     if (user != null) {
@@ -63,9 +63,9 @@ class PackageModel extends BaseModel {
 
   @override
   logout() async {
-    if (customerPackages != null) customerPackages.close();
-    if (packages != null) packages.close();
-    if (activePackages != null) activePackages.close();
+    if (customerPackages != null) customerPackages!.close();
+    if (packages != null) packages!.close();
+    if (activePackages != null) activePackages!.close();
   }
 
   Future<void> _loadPackages(bool isDelivered) async {
@@ -75,15 +75,15 @@ class PackageModel extends BaseModel {
     String path = "/$packages_collection";
 
     try {
-      Query listenerQuery = Firestore.instance
+      Query listenerQuery = FirebaseFirestore.instance
           .collection(path)
           .where("is_delivered", isEqualTo: isDelivered);
-      Query pageQuery = Firestore.instance
+      Query pageQuery = FirebaseFirestore.instance
           .collection(path)
           .where("is_delivered", isEqualTo: isDelivered);
 
       pageQuery = pageQuery.orderBy("update_time", descending: true);
-      packages.refresh(listeningQuery: listenerQuery, pageQuery: pageQuery);
+      packages!.refresh(listeningQuery: listenerQuery, pageQuery: pageQuery);
     } catch (e) {
       log.warning("Error!! $e");
     }
@@ -94,17 +94,17 @@ class PackageModel extends BaseModel {
     String path = "/$packages_collection";
 
     try {
-      Query listenerQuery = Firestore.instance
+      Query listenerQuery = FirebaseFirestore.instance
           .collection(path)
           .where("is_delivered", isEqualTo: isDelivered)
           .where("user_id", isEqualTo: user.id);
-      Query pageQuery = Firestore.instance
+      Query pageQuery = FirebaseFirestore.instance
           .collection(path)
           .where("is_delivered", isEqualTo: isDelivered)
           .where("user_id", isEqualTo: user.id)
           .orderBy("update_time", descending: true);
 
-      customerPackages.refresh(
+      customerPackages!.refresh(
           listeningQuery: listenerQuery, pageQuery: pageQuery);
     } catch (e) {
       log.warning("Error!! $e");
@@ -118,29 +118,30 @@ class PackageModel extends BaseModel {
     String path = "/$packages_collection";
 
     try {
-      Query listenerQuery = Firestore.instance
+      Query listenerQuery = FirebaseFirestore.instance
           .collection(path)
           .where("is_delivered", isEqualTo: false);
-      Query pageQuery = Firestore.instance
+      Query pageQuery = FirebaseFirestore.instance
           .collection(path)
           .where("is_delivered", isEqualTo: false);
 
       pageQuery = pageQuery.orderBy("update_time", descending: true);
-      activePackages.refresh(
+      activePackages!.refresh(
           listeningQuery: listenerQuery, pageQuery: pageQuery);
     } catch (e) {
       log.warning("Error!! $e");
     }
   }
 
-  Future<Package> getPackage(String id) async {
+  Future<Package?> getPackage(String id) async {
     if (user == null) return null;
     String path = "/$packages_collection";
     try {
       DocumentSnapshot snap =
-          await Firestore.instance.collection("$path").document(id).get();
+          await FirebaseFirestore.instance.collection("$path").doc(id).get();
       if (snap.exists) {
-        var package = Package.fromMap(snap.data, snap.documentID);
+        var package =
+            Package.fromMap(snap.data as Map<String, dynamic>, snap.id);
         return package;
       }
     } catch (e) {
@@ -149,18 +150,18 @@ class PackageModel extends BaseModel {
     return null;
   }
 
-  Future<Package> getPackageByTrackingID(String trackingID) async {
+  Future<Package?> getPackageByTrackingID(String trackingID) async {
     if (user == null) return null;
     String path = "/$packages_collection";
     try {
-      var snaps = await Firestore.instance
+      var snaps = await FirebaseFirestore.instance
           .collection("$path")
           .where("tracking_id", isEqualTo: trackingID)
           .where("is_deleted", isEqualTo: false)
-          .getDocuments(source: Source.server);
-      if (snaps.documents.length == 1) {
-        var snap = snaps.documents[0];
-        var package = Package.fromMap(snap.data, snap.documentID);
+          .get(const GetOptions(source: Source.server));
+      if (snaps.docs.length == 1) {
+        var snap = snaps.docs[0];
+        var package = Package.fromMap(snap.data as Map<String, dynamic>, snap.id);
         return package;
       }
     } catch (e) {
@@ -169,35 +170,35 @@ class PackageModel extends BaseModel {
     return null;
   }
 
-  Future<Package> lookupPackage(String trackingID) async {
+  Future<Package?> lookupPackage(String trackingID) async {
     if (user == null) return null;
     String path = "/$packages_collection";
 
     try {
-      var qsnap = await Firestore.instance
+      var qsnap = await FirebaseFirestore.instance
           .collection("$path")
           .where("tracking_id", isEqualTo: trackingID)
           .where("has_user_id", isEqualTo: false)
           .where("is_deleted", isEqualTo: false)
-          .getDocuments(source: Source.server);
-      if (qsnap.documents.length > 0) {
-        var snap = qsnap.documents[0];
+          .get(const GetOptions(source: Source.server));
+      if (qsnap.docs.length > 0) {
+        var snap = qsnap.docs[0];
         if (snap.exists) {
-          var package = Package.fromMap(snap.data, snap.documentID);
+          var package = Package.fromMap(snap.data as Map<String, dynamic>, snap.id);
           return package;
         }
       }
 
-      qsnap = await Firestore.instance
+      qsnap = await FirebaseFirestore.instance
           .collection("$path")
           .where("tracking_id", isEqualTo: trackingID)
           .where("user_id", isEqualTo: user.id)
           .where("is_deleted", isEqualTo: false)
-          .getDocuments(source: Source.server);
-      if (qsnap.documents.length > 0) {
-        var snap = qsnap.documents[0];
+          .get(const GetOptions(source: Source.server));
+      if (qsnap.docs.length > 0) {
+        var snap = qsnap.docs[0];
         if (snap.exists) {
-          var package = Package.fromMap(snap.data, snap.documentID);
+          var package = Package.fromMap(snap.data as Map<String, dynamic>, snap.id);
           return package;
         }
       }
@@ -210,15 +211,15 @@ class PackageModel extends BaseModel {
   Future<List<Package>> getPackages(String userID, List<String> status) async {
     List<Package> packages = [];
     try {
-      var snaps = await Firestore.instance
+      var snaps = await FirebaseFirestore.instance
           .collection("/$packages_collection")
           .where("status", whereIn: status)
           .where("user_id", isEqualTo: userID)
           .where("is_deleted", isEqualTo: false)
-          .getDocuments(source: Source.server);
-      packages = snaps.documents.map((documentSnapshot) {
+          .get(const GetOptions(source: Source.server));
+      packages = snaps.docs.map((documentSnapshot) {
         var p =
-            Package.fromMap(documentSnapshot.data, documentSnapshot.documentID);
+            Package.fromMap(documentSnapshot.data as Map<String, dynamic>, documentSnapshot.id);
         return p;
       }).toList();
     } catch (e) {
@@ -235,22 +236,22 @@ class PackageModel extends BaseModel {
     Future<List<Package>> packages =
         Services.instance.packageService.searchPackage(term);
 
-    Future<List<Package>> packagesFTS =
+    Future<List<Package>?> packagesFTS =
         Services.instance.packageService.ftsSearchPackage(term);
     // Package pkg = await getPackageByTrackingID(term);
     // if (pkg != null && !packages.contains(pkg)) {
     //   packages.insert(0, pkg);
     // }
     List<Package> pkgs = await packages;
-    List<Package> ftsPkgs = await packagesFTS;
-    pkgs.addAll(ftsPkgs);
+    List<Package>? ftsPkgs = await packagesFTS;
+    pkgs.addAll(ftsPkgs!);
     final seen = Set<Package>();
     return pkgs.where((e) => seen.add(e)).toList();
   }
 
   Future<void> createPackages(User user, List<Package> packages) {
     return Services.instance.packageService
-        .createPackages(packages, user.fcsID);
+        .createPackages(packages, user.fcsID!);
   }
 
   Future<void> createReceiving(
@@ -370,10 +371,10 @@ class PackageModel extends BaseModel {
   Future<void> changeDeliveryAddress(
       Package package, DeliveryAddress deliveryAddress) {
     return Services.instance.packageService
-        .changeDeliveryAddress(package.id, deliveryAddress.id);
+        .changeDeliveryAddress(package.id!, deliveryAddress.id!);
   }
 
   Future<void> packageReturn(Package package) {
-    return Services.instance.packageService.packageReturn(package.id);
+    return Services.instance.packageService.packageReturn(package.id!);
   }
 }
diff --git a/lib/pages/widgets/delivery_address_selection.dart b/lib/pages/widgets/delivery_address_selection.dart
index c21a376..1f1b0a6 100644
--- a/lib/pages/widgets/delivery_address_selection.dart
+++ b/lib/pages/widgets/delivery_address_selection.dart
@@ -38,7 +38,7 @@ class _DeliveryAddressSelectionState extends State<DeliveryAddressSelection> {
         Provider.of<DeliveryAddressModel>(context, listen: false);
 
     var deliveryAddresses =
-        await addressModel.getDeliveryAddresses(widget.user!.id);
+        await addressModel.getDeliveryAddresses(widget.user!.id!);
     setState(() {
       this._deliveryAddresses = deliveryAddresses;
     });
@@ -64,7 +64,7 @@ class _DeliveryAddressSelectionState extends State<DeliveryAddressSelection> {
             bool updated = await Navigator.of(context).push(CupertinoPageRoute(
                 builder: (context) =>
                     DeliveryAddressEditor(user: widget.user)));
-            if (updated ?? false) {
+            if (updated) {
               _getDeliverAddresses();
             }
           },
@@ -117,7 +117,7 @@ class _DeliveryAddressSelectionState extends State<DeliveryAddressSelection> {
     bool updated = await Navigator.of(context).push(CupertinoPageRoute(
         builder: (context) => DeliveryAddressEditor(
             user: widget.user, deliveryAddress: deliveryAddress)));
-    if (updated ?? false) {
+    if (updated) {
       _getDeliverAddresses();
     }
   }
diff --git a/lib/pages/widgets/discount_dropdown.dart b/lib/pages/widgets/discount_dropdown.dart
index b4be510..8f00fa7 100644
--- a/lib/pages/widgets/discount_dropdown.dart
+++ b/lib/pages/widgets/discount_dropdown.dart
@@ -53,7 +53,8 @@ class DiscountDropdown<T> extends StatelessWidget {
                   items: values!.map<DropdownMenuItem<T>>((T value) {
                     return DropdownMenuItem<T>(
                       value: value,
-                      child: Text(value == null ? "" : (value as Discount).code,
+                      child: Text(
+                          value == null ? "" : (value as Discount).code!,
                           overflow: TextOverflow.ellipsis,
                           style: TextStyle(color: primaryColor)),
                     );
diff --git a/lib/pages/widgets/my_data_table.dart b/lib/pages/widgets/my_data_table.dart
index 52932b0..3015c50 100644
--- a/lib/pages/widgets/my_data_table.dart
+++ b/lib/pages/widgets/my_data_table.dart
@@ -20,7 +20,7 @@ class MyDataColumn {
   ///
   /// The [label] argument must not be null.
   const MyDataColumn({
-    @required this.label,
+    required this.label,
     this.tooltip,
     this.numeric = false,
     this.onSort,
@@ -40,7 +40,7 @@ class MyDataColumn {
   /// This is a longer description of the column heading, for cases
   /// where the heading might have been abbreviated to keep the column
   /// width to a reasonable size.
-  final String tooltip;
+  final String? tooltip;
 
   /// Whether this column represents numeric data or not.
   ///
@@ -53,7 +53,7 @@ class MyDataColumn {
   /// If null, the column will not be considered sortable.
   ///
   /// See [MyDataTable.sortColumnIndex] and [MyDataTable.sortAscending].
-  final MyDataColumnSortCallback onSort;
+  final MyDataColumnSortCallback? onSort;
 
   bool get _debugInteractive => onSort != null;
 }
diff --git a/lib/pages/widgets/show_multiple_img.dart b/lib/pages/widgets/show_multiple_img.dart
index f94e81d..17e0821 100644
--- a/lib/pages/widgets/show_multiple_img.dart
+++ b/lib/pages/widgets/show_multiple_img.dart
@@ -8,14 +8,14 @@ class ShowMultiImage extends StatefulWidget {
   final List<DisplayImageSource> displayImageSources;
   final int initialPage;
   const ShowMultiImage(
-      {Key key, this.displayImageSources, this.initialPage = 0})
+      {Key? key, required this.displayImageSources, this.initialPage = 0})
       : super(key: key);
   @override
   _ShowMultiImageState createState() => _ShowMultiImageState();
 }
 
 class _ShowMultiImageState extends State<ShowMultiImage> {
-  PageController pageController;
+  late PageController pageController;
   @override
   void initState() {
     pageController = PageController(initialPage: widget.initialPage);
@@ -58,7 +58,7 @@ class _ShowMultiImageState extends State<ShowMultiImage> {
                       value: event == null
                           ? 0
                           : event.cumulativeBytesLoaded /
-                              event.expectedTotalBytes,
+                              event.expectedTotalBytes!,
                     ),
                   ),
                 ),
diff --git a/lib/pages/widgets/status_tree.dart b/lib/pages/widgets/status_tree.dart
index 27e2e49..a01cb7e 100644
--- a/lib/pages/widgets/status_tree.dart
+++ b/lib/pages/widgets/status_tree.dart
@@ -4,7 +4,7 @@ import 'package:fcs/domain/vo/shipment_status.dart';
 import 'package:fcs/helpers/theme.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 import 'package:timeline_list/timeline.dart';
 import 'package:timeline_list/timeline_model.dart';
@@ -12,10 +12,10 @@ import 'package:timeline_list/timeline_model.dart';
 var dateFormatter = new DateFormat('dd MMM yyyy');
 
 class StatusTree extends StatelessWidget {
-  final List<ShipmentStatus> shipmentHistory;
-  final String currentStatus;
+  final List<ShipmentStatus>? shipmentHistory;
+  final String? currentStatus;
 
-  const StatusTree({Key key, this.shipmentHistory, this.currentStatus})
+  const StatusTree({Key? key, this.shipmentHistory, this.currentStatus})
       : super(key: key);
   @override
   Widget build(BuildContext context) {
@@ -39,7 +39,7 @@ class StatusTree extends StatelessWidget {
     if (shipmentHistory == null || currentStatus == null) return [];
     bool isPacked = currentStatus != package_received_status &&
         currentStatus != package_processed_status;
-    return shipmentHistory
+    return shipmentHistory!
         .map((e) => TimelineModel(
             Padding(
               padding: const EdgeInsets.all(18.0),
@@ -48,17 +48,17 @@ class StatusTree extends StatelessWidget {
                 children: <Widget>[
                   Text(e.status,
                       style: TextStyle(
-                          color: e.done ? primaryColor : Colors.grey,
+                          color: e.done! ? primaryColor : Colors.grey,
                           fontSize: 16,
                           fontWeight: FontWeight.bold)),
-                  e.done || isPacked
+                  e.done! || isPacked
                       ? Text(dateFormatter.format(e.date))
                       : Container(),
-                  e.staffName == null ? Container() : Text(e.staffName)
+                  e.staffName == null ? Container() : Text(e.staffName!)
                 ],
               ),
             ),
-            iconBackground: e.done ? primaryColor : Colors.grey,
+            iconBackground: e.done! ? primaryColor : Colors.grey,
             icon: Icon(
               e.status == "shipped"
                   ? Ionicons.ios_airplane
diff --git a/lib/pages/widgets/task_button.dart b/lib/pages/widgets/task_button.dart
index 5ad828c..638cc91 100644
--- a/lib/pages/widgets/task_button.dart
+++ b/lib/pages/widgets/task_button.dart
@@ -9,11 +9,11 @@ typedef BtnCallback();
 
 /// TaskButton is used to navigate to eash task
 class TaskButton extends StatelessWidget {
-  final String titleKey;
-  final IconData icon;
-  final BtnCallback btnCallback;
+  final String? titleKey;
+  final IconData? icon;
+  final BtnCallback? btnCallback;
 
-  const TaskButton(this.titleKey, {Key key, this.icon, this.btnCallback})
+  const TaskButton(this.titleKey, {Key? key, this.icon, this.btnCallback})
       : super(key: key);
 
   @override
@@ -45,7 +45,7 @@ class TaskButton extends StatelessWidget {
             Container(
               height: 45,
               alignment: Alignment.topCenter,
-              child: Text(AppTranslations.of(context).text(titleKey),
+              child: Text(AppTranslations.of(context)!.text(titleKey!),
                   textAlign: TextAlign.center,
                   style: languageModel.isEng
                       ? TextStyle(
diff --git a/lib/pages/widgets/title_with_add_button.dart b/lib/pages/widgets/title_with_add_button.dart
index c006f35..e988f4e 100644
--- a/lib/pages/widgets/title_with_add_button.dart
+++ b/lib/pages/widgets/title_with_add_button.dart
@@ -6,11 +6,11 @@ import 'package:flutter/material.dart';
 import 'callbacks.dart';
 
 class TitleWithAddButton extends StatelessWidget {
-  final IconData iconData;
-  final String titleKey;
-  final OnTap onTap;
+  final IconData? iconData;
+  final String? titleKey;
+  final OnTap? onTap;
 
-  const TitleWithAddButton({Key key, this.iconData, this.titleKey, this.onTap})
+  const TitleWithAddButton({Key? key, this.iconData, this.titleKey, this.onTap})
       : super(key: key);
 
   @override
@@ -28,7 +28,7 @@ class TitleWithAddButton extends StatelessWidget {
             ),
             LocalText(
               context,
-              titleKey,
+              titleKey!,
               color: Colors.black54,
               fontSize: 20,
             )
@@ -40,7 +40,7 @@ class TitleWithAddButton extends StatelessWidget {
             : Padding(
                 padding: const EdgeInsets.only(right: 0),
                 child: IconButton(
-                    onPressed: () => onTap(),
+                    onPressed: () => onTap!(),
                     icon: Icon(
                       Icons.add_circle,
                       color: primaryColor,
diff --git a/pubspec.yaml b/pubspec.yaml
index 557e00e..3153f46 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -14,7 +14,7 @@ dependencies:
 
   cupertino_icons: ^1.0.3
   firebase_core: ^1.5.0
-  cloud_firestore: ^2.5.0
+  cloud_firestore: ^2.5.2
   firebase_storage: ^10.0.2
   firebase_auth: "^3.0.2"
   # firebase_messaging: ^6.0.15