Cannot play media filesTelevisions, Blu-ray players, or other UPnP-compatible playback devices or software cannot play individual photos, videos, or music pieces from the FRITZ!Box media server. When you try to play them, the device may display the error message "not supported file format" or "unknown file format".1 Changing the file extension of MKV video files for use with Samsung devicesSamsung...
> https://en.avm.de/service/knowledge-base/dok/FRITZ-Box-7690/680_Cannot-play-media-files/
Details Automatic heating Your rooms can be heated according to an individual schedule, so you'll always return to a warm home and can forget about turning the radiator on or off. Through automatic switching you'll consume less energy, which saves up to 10 percent of heating costs. You can also adjust the room temperature manually using the button. Turn the switch from anywhere With the FRITZ!Fon...
> https://en.avm.de/products/smart-home/fritzdect-301/details/