" I read most of the post, but didn't notice anything that would work. Ideas?"
"the post"???
Your issue appears to have some similarity to one often reported in the days after an OS update to macOS Catalina—loss of ability to open Nunbers (and Pages) documents.
One suggestion that had many 'that solved it' replies was to restart the computer.
A followup suggestion in cases where that restart was not successful in clearing the issue was to do a restart into safe mode.
To do a 'Safe mode" startup:
- If the computer is shut down: press the power button or key
If the computer is running, choose Restart from the Apple menu
- As soon as you hear the startup chime, press and hold the shift key
- Keep shift pressed until you see the apple logo and a progress bar below it on the screen,then
- release the key and let the startup process finish.
Every startup (including restarts) of the computer triggers a set of housekeeping routines.
A "safe mode" startup runs a larger set of these routines, and omits starting some sections of the OS and its support software.
Because of the extra housekeeping, the "safe mode" startup takes longer than a regular startup. You will also see a degradation in video performance in "safe mode". This is normal.
When the "safe mode' startup has completed, restart the computer again, this time omitting the use of the shift key (ie. a normal restart).
Launch Numbers and attempt to open the problem document(s) again.
Regards,
Barry
