Hi, I have been experiencing this problem at random times, and after a great deal of frustration, I have found something that has certainly worked for me, or should I say the problems seems to have gone away.
essentially in the firewall for the radar rule, on both the client and the server, specified the remote port, I am using the default, 19284, as on my setup the remote port was set to 'any' I know this sounds as if you are tightening the firewall but seems to have worked, this is after a two hour 'soak' test and then system restart and same again, with and without a flightplan, not that the OS should be of any consequence but I am using a Win7 Server and Win10 client both 64 bit.
Hope someone else finds this useful.
