Why is it saying that it cannot play a song in the playlist?
There are mainly two reasons that a song in the playlist cannot be played.
1. When DMS(Digital Media Server) disappears
It is the case that DMS is turned off or network connection has a problem. Turn on DMS and check if DMS is properly
connected to the network.
2. If DMS IP is changed or file location within DMS is changed
You need library synchronization because the sound source location is changed. You can perform library synchronization
in [Settings] > [Music library] > [Synchronization].