If all you need to is uninstall then you don't need the admin console, you can stop everything from the command line:
fmsadmin close (to close all the databases)
fmsadmin stop server (to stop the database engine)
after that you can go to the Windows control panel, stop the FMS services there and proceed to the uninstall
I tried putting that into command prompt and it said it didn't recongize "fmsadmin"?
In Windows you may need the full path:
C:\Program Files\FileMaker\FIleMaker Server\Database Server\fmsadmin
Looks like Java had corrupted itself on a recent update. A reinstall of Java fixed this. Thanks.