When you open a spreadsheet and get the message ”We found a problem with some content in xxx. Do you want us to try recover as much as we can? If you trust the source of this workbook, click Yes’, especially if you just created, it there may be a simple explanation.
On a recent spreadsheet we sent to the client, when they opened it they received this message. When we re-opened it, our own spreadsheet that worked fine, suddenly gave us the same message. We discovered it had to do with the sheet names.
When we entered a sheet name, we were surprised that it allowed us to call the sheet
It did so, so we continued.
However on close and reopen it was these sheet names that it replaced with a Recovered Sheet 1. So nothing was really corrupt and the spreadsheet worked fine. It just didn’t like the sheet name we used, but didn’t stop us from entering it initially.
See if you had any sheet names that had a ‘ in the name.