I try to apply all updates regularly but don't remember when the last program update was. Yesterday, I began having the same problem with all my excel spreadsheets in my OneDrive folder on my computer. The folder is synced to OneDrive, so I can use it offline. I encountered the same problem when not connected to the internet. Last week I used these spreadsheets and had no issues. I devised a workaround by copying the spreadsheets to another folder on the computer not inside the OneDrive folder. I can then access the copied spreadsheet normally without problems.
Today I followed-up on this