Yepo digital audio player

Question

Help! I purchased a Yepo Digital Audio Player (MP3 etc) for my son's birthday and tried to copy some of our downloaded music to the device, but an error message came up stating that there was a format error (these were .wma files). I read online that if you reformated the player it would eliminate the format error, but then I forgot to backup the player's software. Now I still get the format error message and there is no player software on the machine. Is there somewhere online I can download generic freeware to play music and eliminate the format error message? Thanks.