Saved albums losing half the songs

[Jkunsch]

I have a library of downloaded albums for offline play. Today as well as in the past i have lost half of my downloaded material. For example the album "the greatest generation" by the wonder years is still showing that it is downloaded but half of the songs disappeared. I removed it from my library and redownloaded it but the same songs are missing. This has happened to all the albums i have downloaded.

[Duckman13]

This just happened to me. Any solutions?