Product and version: FMS 14.0.4 and 14.0.4a with FM 13.0 (any version up to v5)
OS and version: OS X (various versions) and Windows
Browser and version N/A
Description: see this thread: Re: Error 307 FM 14 Server Upgrade?
How to replicate: See thread above
Workaround: Revert to FMS 14.0.3 or update clients to FM14.