Cant stream mp3 files from NAS

I cant stream mp3 files from my fritzbox with HDD. Then im selecting a file there is no sound but then I skip forward i can hear for a second a sound and then its quiet again. Anyone knows that problem?
Im using 0.53 MBox and the analog output.
Thanks in advance.

Without any logs we are flying blind, try to get some logs that we can work with.