Well, this sucks. I haven't been paying attention to my Amazon music and music storage subscription at all. Apparently Amazon is removing the ability to upload and store any non-Amazon music. They have already shut down the music importer function.
It blows for me because I have the paid storage subscription and have all my music on Amazon. Far more "non-Amazon" music than music purchased at Amazon. Anyway, if anyone else is in the same boat, you might want to start looking at backing up music stored at Amazon to another cloud or local storage device. t looks like this won't be fully implemented for another year, but they appear to be doing it in stages, so I'm not taking any chances.
https://arstechnica.com/gadgets/2017/12/amazon-music-ends-mp3-upload-support-will-end-music-storage-service-in-2019/?amp=1
