Yes there is something, probably a legacy issue between AC10 files and AC11 stuff. Though for this problem I have found a work around. If it crashing upon start up keep opening it, maybe reset your cpu a few times, reset Archicad (option&File New&Reset All), then once you finally get your crappy file with a bunch holes opened after a hour or so, create a teamwork file, update all the drawings, save out every possible file type AC can read.
Basically it's the inverse solution that hardcore teamworkers use to fix consitency issues. If your in teamwork you save out as a pln. Now you are in a pln create a plp. My theory is that there is something messed up with how the files are reading or updating, maybe a ordering issue or something.
But I had this problem today, it started after a simple spell check, and then a 'check for duplicates.' The weird thing was that I had 1400 duplicates, which seemed a little high, I then deleted them and right when I pushed the button 'delete' I/O errors popped up like I've never seem before. It had to be over a hundred, and I knew that if I didn't go through and say okay I was going to loose some valuable work. When quit the file to get a fresh start and came back the file said it couldn't read 22megs of a 26.5meg file. Thus I spent 3 hours going through and updating the drawings which was really abnormally slow, then finally once I could create a plp I did, sent and received a few times, and lost all the errors going through these steps.
There has to be something up with a library part or something within ac11 that doesn't react with ac10 files, some way the CODE was altered between the two versions. I will go to the grave for Archicad and Graphisoft but after the last 6 months on AC11 I feel like GS is digging there own grave and mine along with it.
Archicad 25 (5005), Windows 11, AMD RYZEN 7 3900 (64 GB RAM)