I am currently having similar problems with Archicad 12 as I had with Archicad 11, I continue to use Archicad 10 because of the problem. Basically I run 2 Archicad files, one file to build objects in which I save to a project specific object library, and another file to build the working model which references the object library. My problem is when using the objects in the working model, if I edit the objects in the object working file and reload the library in the working project file the objects disappear and a hotspot will remain. I have to continue to relink the hotspots to the reference object in the object library. Any suggestions as to why this happens