I have the same issue. I just moved my MP3 collection to OneDrive's Music folder. Sync'd to all my devices. On my HTC M8, the Music app found all the music, but I get errors all the time saying the file is unplayable. And then it starts the next song - plays for 5-10 seconds, then error. Skips to next song - repeat.
If I stop it - close the app and go back in, sometimes it will play okay. The only thing I can think of is that it tries to download/stream the MP3 file and if the bandwidth isn't good (weak area when driving), it throws up that generic error. But then it gets in a loop and just keeps doing that over and over even with 4 bars of signal and 30Mbps down speed (LTE).
Getting frustrating.