FMS 11 is running on what WIN or OSX? Win Server ver? OSX server ver? Are you an administrator of Server?
Firewall used? Windows native, third party firewall? Some people mistakenly have two firewalls running.
Rarely Routers can have Firewalls.
There is a free FM Developer forum with users more familiar with FM Server setup and problems.
FileMaker Server is Running on Win Server 2003
Yes, I am an Administrator of the Server.
The Server is within the firewall ( Intranet)
This used to work just fine for years. It seems to have something to do with the Java 7 Update 45 or 55
I went to Java settings and set the Security Setting to Medium and now works. See Picture.