Contacts gone after Yosemite upgrade
I hit the exact same bug, or a similar one.
After upgrading my MacBook Air (11-inch, Mid 2012) from the latest version of Mavericks to Yosemite 10.10.1, everything appeared to go flawlessly — until I opened my Contacts and found it completely empty.
Luckily I have a desktop Mac Mini with my Contacts (I use ChronoSync to periodically keep laptop's Contacts synced with my Mini). In fact, the reason I upgraded to Yosemite on my laptop first is to make sure that there would be no glitches before upgrading my Mini. It seems that was a very good idea!
I first tried replacing the AddressBook folder on my MacBook Air:
with a copy of this folder from my Mini. That worked, and when I opened Contacts all my data were back. Cool, I thought. But after quitting and re-opening Contacts, the data were gone and I was back to a fresh, empty Contacts.
Then I tried exporting the data from my Mini, using Contact's "Export…" feature. Then I had a file called:
Contacts - 11-21-2014.abbu
I opened my empty Contacts on my Air and used the "Import…" feature to import the data. That worked, but again, after quitting and re-opening Contacts, the data were gone and I was back to a fresh, empty Contacts.
This is extremely frustrating, to say the least. A pretty major bug, which renders my Contacts unusable.
BTW, I at no time was I logged in to iCloud. I do not use, and have never used, iCloud, for anything.
Does anyone know how to fix this bug?