Thanks a lot

Well I noticed something:
I had installed the native Version for M1 of VLC. I now tested with the latest Intel build of VLC and got a pop-up notifying me that DVDpedia wants access to control VLC (paraphrasing because my MacOS is in German), after allowing this everything works as expected. I don't get a pop-up with the VLC for M1.
I also noticed while working on this reply:
VLC(M1) actually starts in the background and sits there doing nothing, no file in playlist.
This seems to be significant.
To test I changed “Open with:” for a movie to QuickTime. It starts playing inline in DVDpedia.
I also tried the native version of IINA and that works too. Problem is, that version is still buggy.
So DVDpedia and VLC(M1) seem to have problems talking to each other. Is this only on my machine, or on other M1s as well?
I did the tests as well in regular release as in the beta. The difference in the beta is that the program doesn't hang/beachball. Otherwise same as above.
Finally I updated MacOS to 11.2.1 (20D74) and tried all the above again in regular release as well as the beta: No changes.
My answers to your other questions/suggestions:
FineWine wrote:Is this the app store release of DVDpedia 6.1.0 ?
No, download from bruji.
Exactly same behaviour.
These are the Folders and Files that should be in ~/Library/Application Support/*****pedia/ .
When I got the exported backup from the old Mac I already deleted most of that stuff, I just tried once more with latest release as well as beta and kept only the necessary data.
Keep in mind this is a new machine.
Also there are some hidden menu tasks that you can perform: 'hold down the option key and click on the main Help menu in each program once and select - each in turn: 'Verify Database', 'Remove Orphaned Covers' and 'Clean Duplicates in Fields'
That didn't help either.
And finally if your particular pedia is actually crashing do check for the Crash Logs. You can find the relevant logs in your Home folder under: ~/Library/Logs/DiagnosticReports/
There I can only find files with names starting with: “CloudServicesTopic…”, “KeySyncTopic…”, “NetworkingTopic…” and a file relating to AdGuard.