A client recently purchase a new Mac Mini (with Yosemite) to be a dedicates server for FileMaker Server 13. After installing FileMaker Server 13 on the machine, however, none of the databases, including the FileMaker Sample file, would open.
After quite a bit of research, we finally found the answer. It has to do with matching the sharing name of the computer with the FM Server instance name. The video shows all of the details of the problem and the fix.
The purpose of the video? Hopefully, you will be able to find this solution faster than we could in FileMaker's support site and on their forum.
By the way, we also encountered problems with this machine authenticating to a Windows Server 2012 R2 domain controller, making it impossible to use Active Directory external authentication for logon. That, once figured out, will be a separate video.