Not with Fire TV Stick

I was hoping that I have with this app to access my media server (Twonky) to watch recorded by me and cut with TS-Doctor Video files.
In the network, the app moves swiftly, media server and SMB shares are quickly detected, the navigation in the folder structure provided by Twonky running smoothly.
However, I did when playing the video files no sound or only "hard noise".

Currently for me so useless.