Lately our office has been experiencing trouble accessing our databases - either over the local network, or remotely, offsite (via VPN access). Loading time is super slow, even scrolling through records gets it hung up and the db shuts. Often the window with the "communication with host could not be re-established..." error shows up and all windows close.

We can access our networked volumes/folders/files fine. This issue seems to be particular to FMPro/FMServer.

Sometimes it goes away after a server restart and other times it seems to resolve itself. I can't think of anything that was done to the server recently that would have affected FMServer (We are running 9, clients on FMP 9 or 8.5).

Our server is connected to a switch that connects to our modem/router. Not sure if that plays in anywhere since i have yet to experience a hang up with anything else over the network.?

Is the FMS machine dedicated to FMS or are there other things running on it? What's the OS on the server?

Note that the fact that you can access shares elsewhere on the network is not a good reference test to conclude that there are no network problems. The nature of the client/server traffic between FMP and FMS is unlike most other things on the network. There is a lot more 2-way time-critical communication going on between FMP and FMS.