From the exception you posted it looks like your svn unity plugin encountered an error. You also said that once you start reimporting unity crashes. I have a suspicion that those problems could be related. Usually SVN will handle binary files by using Locks, to enforce those locks SVN usually sets the read only flag on those affected files. Inside the Generated/Resources folder all files can be ignored by the Version Control system. Because they will be rebuilt using a re import.
This should not be a problem, because even if the file is readonly i'm confident that the plugin and unity will handle those gracefully and not just plain crash to the desktop.
Just an idea going through your posts again.
I will now try to recreate the issues with your data.
Best regards
Nico