Parallels Desktop 26 on MacOS Ventura very slow to start, wants to restart Mac on each launch

I just upgraded to Parallels Desktop 26 (26.1.1) on MacOS Ventura (13.7.8), and it looks like I shouldn't have.
Any time I start Parallels Desktop, it says "Starting..." for a very long time.
After a while, it will say that it needs to restart the Mac.
After a restart, it will display "Starting..." again for quite some time.
This makes using Parallels virtually impossible, I can't wait 30 minutes or more and restart my Mac every time I need to run a VM.
I already tried the workaround suggested in https://kb.parallels.com/en/129191 (which was supposed to be fixed in 18.1.0), no change.
What can I do?

 

I had the exact same problem !
The solution was to remove the preferences directory of Parallels completely:
sudo rm /Library/Preferences/Parallels/
or remove it using Finder
After months of struggling with very slow starts, or even not possible to start, all seems fine now. Hopefully you will get it to work as well.