Attendance

So I have some classes in which I cannot do a quick all attendance, yet others I can. Also how to I revert to a blank gradebook rather than the template.

Any ideas????

HELLO.
All classes behave the same. Make sure the column is actually an attendance one.
If can't sort it out, a screenshot would help a lot.
Regarding the blank gradebook, you shouldn't erase your data, just create a new class or create a new tab. If despite this you still want to erase your data: Open your gradebook > Tools (top bar) > Columns > All > Delete but this is not recommended