We have tried loading AC 12 and AC migration 11 in different configurations. In the beginning, our default was simply placing the ArchiCAD 11 Migration Library in the ArchiCad 12 folder and selecting it separately in the Library manager, so as a result we had the AC12, ArchiCAD 11 Migration Library, and 3 other libraries (that include CADimage and a couple project specific libraries). That was the first configuration and the one where we first realized that we had a problem.

From there, I experimented with several locations with them all bearing the same result.

By the way, you can see in our screenshot that we placed a folder of "Object Library 9 and 10" objects (older migrations files) in the main "ArchiCAD Library 12" folder. Through using the AC 11, this had always worked for us, so we assume that placing the ArchiCAD 11 Migration Library into a similar location might be the solution. But it was not.

I wanted to add another screen and show the library manager. I will send another post.

Here is the screen shot of the Library manager. this is the configuration we started with.

While I am at it, here is a shot of the library report. You asked what the results were, so I wanted to answer that.

Answers:
1. The file "ArchiCAD 11 Migration Library.lcf" is 49.6 MB.
2. Either it came from the AC 12 disk or I downloaded it, but I am finding evidence that it an USA version. see the screen shot below
3. We do not see AC 11 objects shown missing in the report. In fact, we do not see any AC11 objects at all I think. But again, old AC9 and 10 objects do appear. Keep in mind I have those migration libraries loaded.

Just discovered that the problem only happens through Hotlinks. When a hotlink file is opened, the objects are there. Somehow, they come up missing by the host file.