Hi jademan!
Now I’m happy because I was able to fix my file.
There is no way to fix this error for my Mac, but there is for Windows. So I re-uploaded the file to Windows and fixed it, as it says here https://forum.audacityteam.org/t/corrupt-or-otherwise-broken-audacity-project-recovery/64162/1 and it worked!
You are doing a very great job. I was desperate this morning, and now I can work with my podcast again. Thank you for what you are doing, thank you for your help and thank you for new knowledge 
Have a nice day!