Unable to Open a Numbers File Updated Today on iMac Running Catalina 10.15.7

On my iMac, I just updated a Numbers file, only to discover I am unable to re-open it. The error message is:

"file can't be opened right now. Numbers couldn't read the file. You can try restoring to a previous version."

However, I am unable to retrieve previous versions using Time Capsule. Please advise, as I encountered this same issue with Pages files. I tried re-starting my iMac, but it didn't resolve the issue.