This player does not support copyright protected (DRM) WMA tracks bought from the Internet
The song might be in a format that is not supported by the player. Only MP3, WMA and WAV files are supported
The audio file might be corrupted, try to playback the file on your PC first, If it does not play, RIP the song again
The player can support maximum 500 files and folders
Some of those music tracks may be in a format or bit rate that is not supported by the Digital Audio player like AAC or files in variable bit rate may be skipped by the player. (For MP3 the player supports 32 –320kbps & for WMA: 5-192kbps with sampling rate 8.0kHz up to 44.1kHz)