Subassembly Composer 2013 Error message

[Anonymous]

I get this strange error message in the sub assembly composer 2013.  Here's a screen shot:

I never saw it before installing Microsoft .NET 4.5 in order to be able to bring a custom sub assembly into Civil 3D 2013 with SP 2 installed as suggested in this thread:

http://http://forums.autodesk.com/t5/AutoCAD-Civil-3D-General/Civil-3D-2013-Servicepack-2/td-p/43573...

The message seems to pop up after I minimize the subassembly composer and leave it alone for a few minutes. It's a real nuisance since I have to exit the sub assembly composer and open it up again in order to get the message to go away.  I have the Sub Assembly Composer split into two screens with the preview panel maximized on one screen and all of the other panels on the other screen. It seems like that may be part of the problem but I'm not entirely sure.

Any thoughts?