Numbers crashing on launch

I have seen numerous posts throughout the discussions addressing this same issue -- with varying levels of success. None have worked for me thus far.

I have a M1 MacBook Air with Big Sur and it has been flawless for the past 7 months. Yesterday while working in Numbers the app hung up -- swirly beach ball -- after attempting to open a document in dropbox. I did not realize at the time that my internet connection was down so apparently the app locked up while trying to open a document that was not on the local hard drive.

I forced quit and relaunched Numbers but every time I attempted to open the file it locked up (because it was offline.) I finally realized the issue. Got the internet working and launched Numbers. But this time is crashed immediately. I tried again and again. I then decided to restart my MacBook. When it launched Spotify launched at login and also crashed. I then attempted to open other apps to test which would open. All did except for Spotify, Numbers, Pages and KeyNote. After a few restarts Spotify began to open fine. The iWorks apps did not.

Searching various solution in the discussions I was able to get Pages and Keynote working by restoring Font Book. Numbers still crashes.

I have done most -- if not all -- of the fixes. Some like deleting the .plist file do not apply since there no longer is a com.apple.iworks.plist file. Some highlights: I have uninstalled and reinstalled the app. I have open files with shift key down. I ran disk first aid.

I have tried everything short of logging out of iCloud and logging back in which was another suggestion. I started to do so but was freaked about all the questions and asking if I was SURE I wanted to log out because everything would be gone. I know it's in the cloud but I really want to make sure this will work before I go through the hassle of having to reload all my photos, documents, emails, contacts, events etc -- and their preferences.

I feel like I am screaming into the wind but I need to access years of numbers documents for reference in my job. And unlike Numbers which CAN open excel documents, I cannot open a numbers document in excel. My workaround is to have my assistant open the documents and send them tom me as an excel but that will only do for so long.

Thanks for reading this far.