1.Run flutter upgrade in the terminal to upgrade Flutter
2.Run dart migrate to run the dart migration tool
3.Solve all errors which the migration tool shows
4.Run flutter pub outdated --mode=null-safety to print all outdated packages
5.Run flutter pub upgrade --null-safety to upgrade all packages automatically
6.Check the code for errors and solve them
7.Run dart migrate again and it should now be successful. Follow the link to checkout the proposed changes
8.Press the "Apply Migration" button
9.Check the code for errors again and fix them.
Run flutter run in the command line and the application should run...
Note: If there are any library in you project that don't support null safety you must need to upgrade that library. if that library don’t have null safety remove the library and use another library
I found this solution, you can check this:
cre: Flutter: Execution failed for task ':agora_rtc_engine:compileDebugKotlin'
1.Run flutter upgrade in the terminal to upgrade Flutter
2.Run dart migrate to run the dart migration tool
3.Solve all errors which the migration tool shows
4.Run flutter pub outdated --mode=null-safety to print all outdated packages
5.Run flutter pub upgrade --null-safety to upgrade all packages automatically
6.Check the code for errors and solve them
7.Run dart migrate again and it should now be successful. Follow the link to checkout the proposed changes
8.Press the "Apply Migration" button
9.Check the code for errors again and fix them.
Run flutter run in the command line and the application should run...
Note: If there are any library in you project that don't support null safety you must need to upgrade that library. if that library don’t have null safety remove the library and use another library