TIM CIMBURA has information on Mavericks causing FileMaker network issues and disconnects:
We’ve noticed some issues lately with some FileMaker clients running on Mac OS 10.9 Mavericks. They include random disconnects from the server. The following error messages may appear as a symptom of this issue:“Communication with the host was interrupted and could not be re-established. All affected windows will be closed.”
or“Client "xxxx (XXXXXXXXXX) [x.x.x.x]” no longer responding. Connection closed. (Error 51)”
This is a feature of Mavericks that is new to me. Good catch, Tim! And if the trouble persists, there is a list of other handy fixes to try.