Guys, thanks for the offered help! I'm currently away on vacation and will try your suggestions once more once I'm back. Anton, I was already on Windows 11 and did the official service update. And I already have tried the clean uninstallation / re-installation, which leads to clothworks working as it should - until I close Sketchup and reopen it, then it starts crashing.
Dave, I don't get a bug splat window, it just closes immediately. I am running a legit Sketchup and clothworks license. If it was a windows / graphic driver related issue, I doubt I could get it to work after a fresh reinstall. I've got a RTX 3090.
Thanks so far for your help, I'll keep you posted!
cheers