I have a gtx 560 ti and I have been crashing frequently too
Recently however I went a long time without crashing (about six hours).
But when I went to Hoelbrak with my lvl 21 Ranger to do some “dread” something quest I crashed when I left my story instance and tried to get into hoelbrak.
Now whenever I try to reload that character who is currently in hoelbrak (Ive tried about 4 times in a row) I get the error posted below.
I think it is odd that all my other toons in different areas work but I cant get past the load screen when I try to log in my ranger on hoelbrak. I have repaired the game twice after encountering this issue with little success.