I noticed for 2-3 weeks randomly my server2012R2 isn't accessible anymore.

reboot is the only thing that works.

After a while I figured out exactly when this happens, but not every time, but ONLY under following conditions:

Since 2-3 weeks I have a raspberry pi installed with OpenElec.
On the OpenElec I have the mezzmo plugin to play movies from the Mezzmo which is running on my server2012R2

When someone clicks on this plugin on the OpenElec, it sometimes kills the Server2012R2

There is NO error report
There is NO crash
PING still works

but I can't use remote desktop connection
I can't even navigate the mouse on the Server2012R2
I can't close or open a window
I can't control-alt-del

and thus far this ONLY happens when the mezzmo plugin on the Openelec running on Raspberry Pi is started
BUT not every time it is started.

So to the Gurus here online.. suggestions?

I'm using mezzmo in the server2012R2 for years with 0 problems
I am using uPNP players on the ipad, iphone, samsung TV, panasonic UPNP TV, etc..

no problems ever..

except since I started to use the Raspberry Pi with Openelec and Mezzmo plugin...