This isn't a crash technically... You are already closing your AutoCAD Vertical session when this comes up. From a few threads that I have read, basically your session is holding onto an AEC module during the exit process, and the session isn't releasing it properly as it closes.
This is a very harmless error. Some have claimed that it is due to installing 2013. I disagree since I get the error and have never installed 2013! Some have reported that a repair of 2012 pruducts fixes the error. Again not my experience.
The last thread gives what I think is the best plausible reason for the error, see Peter Funk's reply no 11. ~ Mary
___________________________________________________________________ Normal people believe that if it ain't broke, don't fix it. Software Engineers believe that if it ain't broke, it doesn't have enough features yet.