Anyone immune to the bug "Unrecoverable Internal Error on Line 422"?

It seems that it's very common for assassins to halt and crash game. I did a search, people blame COS/shadow master/BOS, etc. However, in my experience, those ain't the root of the problem. Any one has insight to share?|||Might help to offer what you consider to be the root of the problem.|||I've only had Assassins crash the game when I cast CoS where there are a lot of static enemies (primarily those pole zombies in Act 4), and with the Ancients.|||I just had an "Unrecoverable Internal Error" while in town. I suspect memory leak.