Yahoo drm - purchaced downloads won't play

A large number of tracks in my music library will not play. All tracks were purchased; most of the effected tracks are downloads. About three months ago this problem appeared. Windows Media Player would not play tracks and the error message stated that the tracks were drm protected and I need to purchase or reacquire license from Yahoo. Again, all music was purchased. Attempts to reacquire license when logged in to Yahoo fail. Steps taken to correct for possible corrupted drm folder did not resolve problem. Yahoo tech no support has promised for months to help but just gives me the run around and tells me someone will help........they do not. Recently purchased downloads from Amazon are unplayable in Real Player because and the error message states that Yahoo says that I do not have on the licenses for the tracks that I just bought. If someone can help it would be most appreciated.
Thanks,
Greg