Buffer Overrun Detected Error Crash

[Krokpot]

All of a sudden tonight I'm getting the following error

Buffer overrun detected!

A buffer overrun has been detected which has corruptd the program's internal state. The program cannot safely continue execution and mush now be terminated.

then the game crashes to desktop when I click "ok"

this happens once I log in and either get to the character select screen or when I click ok to log in my character if the char select screen loads.

any thoughts on how to fix?