I had this issue yesterday with a fresh ISO install of 3.0. I selected all the modules I wanted to install when I was initially configuring the server and ended up with that error(File sharing version 3.0.14). I reinstalled from the ISO yesterday, installed network, ntp, users and dns without updating anything. Selected use PAM under user and groups, rebooted and installed File Sharing(version 3.0.15). I was able to make a test user, group and share today and it appears to work ok.