Yosemite Server app hangs
I'm trying to migrate from an old MacPro running 10.6 Server to a newer MacPro and Yosemite Server. Migration assistant moved a lot, but failed to move the OD users, so I'm trying to do that manually. I installed the Yosemite Server app, but when I run it it hangs, saying "Reading Open Directory settings." I let it run ~24 hours before Force Quitting (the only option). I tried the suggestion at (OS X Server (Mavericks): Remove pre-release version before installing OS X Server - Apple Support), but it made no difference. Any suggestions?
Mac Pro, OS X Yosemite (10.10.3)