Open DWG file and some/most elements are locked.
Product: MicroStation Version: V8 and V8iArea: DWG-Open
Use Element ID on element. If Information shows element is Shared Cell with either DWG Proxy or AEC name, it is an element created using one of the AutoDesk Desktop Products.
AutoCAD will not display/manipulate these elements either without running the Desktop Product or one of the Enablers.
If ProxyGraphics is set to 1 in ACAD, proxy images of these elements will appear.
If set to 0, only bounding boxes will appear. To unlock, go to Edit > Select All, then Edit > Unlock. Elements can now be deleted/moved.