Error 500, every 5 minutes!

Error 500, every 5 minutes!

There is a constant error that makes it impossible to work with Sheets (I've faced it in Write too)
It is this "Error 500: Internal Server Error" that asks to reopen the sheet, but it does it 100 times a day, almost every 5 minutes!!!

Please help because a job that should take 10 minutes, wastes an hour!

Thanks,

Ali