I have the same problem as well.
I’m on a company computer and left for the holidays. Came back and Yosemite was installed.
Sat with a client this morning for 3 hours reading blog posts / the Resolve manual trying to figure out how to get my libraries back and nothing is working.
For some reason only one directory is working, which is the ‘Movies’ (/users/myname/movies) folder and is also my designated cache directory. It’s the only directory that I can see the folders in my Library panel in Resolve. :/
My current solution is I’ve cleared space on the HD and now I’m transferring the footage to that folder to work from there.