Flutter Run : FAILURE Build failed with an exception - flutter

Question

Please help me. Since I cloned this project from git I always get the following error message
../../../AppData/Local/Pub/Cache/hosted/pub.dev/flutter_math_fork-0.5.0/lib/src/encoder/tex/functions/frac.dart:113:37: Error: The getter 'optionsDiff' isn't defined for the class 'GreenNode'.
- 'GreenNode' is from 'package:flutter_math_fork/src/ast/syntax_tree.dart' ('../../../AppData/Local/Pub/Cache/hosted/pub.dev/flutter_math_fork-0.5.0/lib/src/ast/syntax_tree.dart').
Try correcting the name to the name of an existing getter, or defining a getter or field named 'optionsDiff'.
final remainingOptions = node.optionsDiff.removeStyle();
^^^^^^^^^^^
../../../AppData/Local/Pub/Cache/hosted/pub.dev/flutter_math_fork-0.5.0/lib/src/encoder/tex/functions/frac.dart:138:37: Error: The getter 'optionsDiff' isn't defined for the class 'GreenNode'.
- 'GreenNode' is from 'package:flutter_math_fork/src/ast/syntax_tree.dart' ('../../../AppData/Local/Pub/Cache/hosted/pub.dev/flutter_math_fork-0.5.0/lib/src/ast/syntax_tree.dart').
Try correcting the name to the name of an existing getter, or defining a getter or field named 'optionsDiff'.
final remainingOptions = node.optionsDiff.removeStyle();
^^^^^^^^^^^
Target kernel_snapshot failed: Exception
FAILURE: Build failed with an exception.
* Where:
Script 'C:\SRC\flutter\packages\flutter_tools\gradle\flutter.gradle' line: 1151
* What went wrong:
Execution failed for task ':app:compileFlutterBuildDevDebug'.
> Process 'command 'C:\SRC\flutter\bin\flutter.bat'' finished with non-zero exit value 1
* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.
* Get more help at https://help.gradle.org
BUILD FAILED in 8s
Running Gradle task 'assembleDebug'... 9.6s
Exception: Gradle task assembleDebug failed with exit code 1
I have tried
flutter pub get
flutter clean
But still, get the error message above. I am getting error messages only in this project. if I do flutter run in another project it can run without problem.