Hi when compiling my project I am getting the following errors:
../flutter/flutter/.pub-cache/hosted/pub.dartlang.org/syncfusion_flutter_core-18.2.44/lib/src/theme/barcodes_theme.dart:45:31: Error: Type 'DiagnosticableMixin' not found.
class SfBarcodeThemeData with DiagnosticableMixin {
^^^^^^^^^^^^^^^^^^^
../flutter/flutter/.pub-cache/hosted/pub.dartlang.org/syncfusion_flutter_core-18.2.44/lib/src/theme/calendar_theme.dart:45:32: Error: Type 'DiagnosticableMixin' not found.
class SfCalendarThemeData with DiagnosticableMixin {
^^^^^^^^^^^^^^^^^^^
../flutter/flutter/.pub-cache/hosted/pub.dartlang.org/syncfusion_flutter_core-18.2.44/lib/src/theme/charts_theme.dart:45:29: Error: Type 'DiagnosticableMixin' not found.
class SfChartThemeData with DiagnosticableMixin {
../flutter/flutter/.pub-cache/hosted/pub.dartlang.org/syncfusion_flutter_core-18.2.44/lib/src/theme/datagrid_theme.dart:45:32: Error: Type 'DiagnosticableMixin' not found.
class SfDataGridThemeData with DiagnosticableMixin {
^^^^^^^^^^^^^^^^^^^
../flutter/flutter/.pub-cache/hosted/pub.dartlang.org/syncfusion_flutter_core-18.2.44/lib/src/theme/daterangepicker_theme.dart:47:39: Error: Type 'DiagnosticableMixin' not found.
class SfDateRangePickerThemeData with DiagnosticableMixin {
^^^^^^^^^^^^^^^^^^^
../flutter/flutter/.pub-cache/hosted/pub.dartlang.org/syncfusion_flutter_core-18.2.44/lib/src/theme/gauges_theme.dart:45:29: Error: Type 'DiagnosticableMixin' not found.
class SfGaugeThemeData with DiagnosticableMixin {
../flutter/flutter/.pub-cache/hosted/pub.dartlang.org/syncfusion_flutter_core-18.2.44/lib/src/theme/maps_theme.dart:44:28: Error: Type 'DiagnosticableMixin' not found.
class SfMapsThemeData with DiagnosticableMixin {
^^^^^^^^^^^^^^^^^^^
../flutter/flutter/.pub-cache/hosted/pub.dartlang.org/syncfusion_flutter_core-18.2.44/lib/src/theme/slider_theme.dart:40:30: Error: Type 'DiagnosticableMixin' not found.
class SfSliderThemeData with DiagnosticableMixin {
^^^^^^^^^^^^^^^^^^^
../flutter/flutter/.pub-cache/hosted/pub.dartlang.org/syncfusion_flutter_core-18.2.44/lib/src/theme/theme_widget.dart:75:24: Error: Type 'DiagnosticableMixin' not found.
class SfThemeData with DiagnosticableMixin {
^^^^^^^^^^^^^^^^^^^
../flutter/flutter/.pub-cache/hosted/pub.dartlang.org/syncfusion_flutter_core-18.2.44/lib/src/theme/barcodes_theme.dart:45:7: Error: The type 'DiagnosticableMixin' can't be mixed in.
class SfBarcodeThemeData with DiagnosticableMixin {
^
../flutter/flutter/.pub-cache/hosted/pub.dartlang.org/syncfusion_flutter_core-18.2.44/lib/src/theme/calendar_theme.dart:45:7: Error: The type 'DiagnosticableMixin' can't be mixed in.
class SfCalendarThemeData with DiagnosticableMixin {
And the same again a few more times.
Flutter Doctor output :
[✓] Flutter (Channel stable, 1.20.3, on Mac OS X 10.15.6 19G2021, locale en-US)
[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
[✓] Xcode - develop for iOS and macOS (Xcode 11.7)
[✓] Android Studio (version 4.0)
[✓] VS Code (version 1.44.0)
[✓] Connected device (1 available)
I am using syncfusion_flutter_datepicker: ^18.1.57-beta
Could you please let me know how I can resolve this?