Unable to synchronize models in VDB

I took the Books example and, after fixing the broken transformation SQL, went to synch the VDB (prior to deployment). When I started the VDB editor I saw none of the models were in synch, but the Synchronize All button was disabled. Also found I could not check any of the synch check boxes.

Restarted the Designer with the same result.

This project had once contained the corrupt "Parts Project" folder and may be suffering from that in some weird way (since I deleted it).