Android App Crash: FATAL EXCEPTION: main - ClassCastException: com.example.pg_helper.Frame cannot be cast to com.example.pg_helper.MainActivity

This error occurs when trying to cast an object of type 'Frame' to 'MainActivity'. The error is thrown in the 'TableFragment' class at line 81.

To fix this issue, you need to ensure that the object being casted is of the correct type. Check the code in 'TableFragment' and make sure that you are casting the correct object.

If you are not sure why this error is occurring, you can provide more information about the code in 'TableFragment' and 'MainActivity' so that we can help you further.