Plex for Popcorn Hour A400 - IP does not work

Hi,

ive got a media player called Popcorn Hour A400.
It supports adds, and there is one called "Plex v1.0.9".

I installed it and tryed to start it, but i have Problems with the setup:

(My Thecus NAS installed with Plex Module is at IP 192.168.0.77)

So i tried this IP, but it seems not to be correct:

"no connection to Media Server. Please check IP adress and Port"