Comment 2 for bug 1512608

For the failing files, do they actually contain embedded artwork, or just the artist and album tags? If the latter, the artwork comes from the remote image server. If the server can't be reached or is temporarily out of action, you won't get a thumbnail. As of OTA-8, we retry once every few hours if the server cannot be reached so, once you have OTA-8, the situation should rectify itself automatically.

If your files *do* contain embedded artwork, could you please attach one of the failing files (with its original file name intact) so we can have a look?