Sorry to be slow answering this question. I didn't get a notification from the Forum.
When Mac upgraded MacOS to Catalina, they dropped some files that WINE needed to make Donor Manager run.
So, we need to switch to using Crossover from CodeWeavers to run DM (and it runs great!)
Crossover is a commercial program ($ 60) but has a 14 day trial.
https://codeweavers.com
Once it is installed, you will then have it run the "Full Installer" of the Donor Manager (do a fresh download from the DM website) and then run the program once.
It will install (generally quite easily) but it will not be able to find your previous installation's data files.
Now, if you have a recent "Pack and Go" file, then you can simply restore that from within the new Crossover / Donor Manager.
But, if you don't have a recent "Pack and Go" / Data transfer file, then the process is a bit tricky as both WINE and Crossover put their data files in "hidden" folder on the Mac.
Let me know and I can walk you through the process of finding those hidden folders, or we can do a remote access session and I can help you do it live. It generally takes just a few minutes to do.
John