This has happened to me twice. I opened my gradebook and categories such as "weight" and "total marks" have suddenly disappeared from my assignments, and as a result when I try to import grades from Classroom, I get this error message:
Error: Import unsuccessful: Exception: The number of columns in the data does not match the number of columns in the range. The data has 313 but the range has 312.
Do I need an update? I can't afford to keep losing my grades!