Same problem here, starting from today. I seem to be able to play any music that I added to My Music Library prior to today, but when I attempt to play anything added to the Library today, it just skips through the tracks without playing. Also don't seem to be able to remove anything from My Music Library. All works fine on iPad and iPhone, just an issue with MAC. Have tried rebooting, logging out and in of account within iTunes, and removing and re-adding Music Library from within iTunes preferences, and nothing seems to work. Hoping someone on here will come up with a solution before Apple get round to acknowledging the problem,