Exception warning on every close

For about a week or so, everytime I close AutoCAD Mechanical 2014 (part of Inventor Pro, used with Vanilla-based profile), I now get this:

The writing / address changes, but the C000005 involving accoremgd.dll is the constant.

I don't lose anything, so it's more of an annoyance.  I'm up to date on SPs, as far as I can tell.