Has anyone ever seen the following error? We're running ACAD 2006, but have 2006 Mechanical installed. No use for the Mechanical, so just using the 2006. We have drawings with simple 2D blocks in it, with a few attributes, and when a block is double-clicked (Edit Attribute in right-click menu) to open the "Enhanced Attribute Editor", the following ACAD error pops up. I've attached the screen shot of the pop-up. After clicking OK, the Editor opens and works fine.
!tills.cpp@52: enullobjectid