DMA-2500 problems over network

Bikeballer

Hello Community;
I have problems streaming DTS video files over my network.
If I play the file directly via a USB stick to the DMA, it runs, otherwise Error 301 comes.
Does anyone have a solution?
My network:
Fritz box 7590
Netgear GS108T Switch
Synology DS1517 +

#Others_Feb_2019