Won't save, won't export. What happened to Audacity?

I just updated to the new Audacity 2.4.1.0 so it would be compatible with the latest Mac OS (Catalina 10.15.4)

First I had problems with the playback sound not working after at first it did work. Suddenly it just stopped producing sound.

Then I tried to close the file but it wouldn’t save. It said:
“Could not save project. Perhaps /Users/ericrosenfeld/Desktop/First Narration for Germany Video
is not writable or the disk is full”

I looked that message up and found that other people had same problem with no solution found!

So I decided to export the file instead. This is where it gets truly horrible.
It didn’t export, and it also erased my audio tracks!
Hitting “edit > undo” didn’t help either!!!
No, this is not a joke!

Looks like the new Audacity is incompatible with my Mac.
Or what else could be happening?

This is awful.

Eric