Not all the time, just randomly freezes when accepting quests, have to restart game

Sorry, my bad. Thank you for clarifying it.

If you google "Warcraft freeze quest" or "Warcraft crash quest" and filter the results by recent week, you will find some matches.

I didn't make any changes to quest accepting process, and I can't think of any reason on my end that could suddenly cause this after pre-patch. So I'm afraid there is nothing I can do to help at this moment.