Archive Manager in 20.04 will not extract files from password protected zip files from 18.04
After upgrading to ubuntu 20.04, I had the same issue. I got the error "An error occurred while extracting files" while trying to extract a password protected zip file.
After installing p7zip-full:
sudo apt install p7zip-full
The same archive manager could extract the files without issue.
WARNING: @Henrik R. warns that after installing he couldn't extract password protected files anymore that he'd already made on ubuntu 20.04. He coud again after removing p7zip-full
$ sudo apt remove p7zip-full