Background: I was attempting to export one of the gun emplacements are alter it's shape to look like the guns from the WWI era. I exported the shape 20mmext (tried 20mmint too). I made superficial changes and re-imported. Placed in my terrain and set type to "Auto Gun" and when I tried to run the terrain offline, it CTD. So I assumed I edited something wrong. I decided to do a simpler test.
Test: Exported the shape 20mmint. Simply changed the name and re-imported it. Placed into terrain, set type as "Auto Gun" and when I ran the terrain offline, CTD.
Notes: Looking at the groups and polys in edit tree between the original and the re-imported, the DOF groups and polys are not colored the same in the tree nodes. I think some property is not correct, even though in the simple test, there was only a name change.
Remaining questions: I don't know if this is an intended behavior. Is it a security protection to prevent hacking? If so, then I would not have thought it would be offered for export or some other behavior besides CTD. Or possibly it is another instance of object properties getting broken somewhere in the export/import workflow as might be the case in this other issue:
https://bbs.hitechcreations.com/smf/index.php/topic,395004.0.html.
I can provide you an example of the exported *.ac file if that would help.