Possibly worthwhile deveopment: All the subscription music that I have that I couldn't play through Zune because of the DRM error DOES play in Groove. I just assume that means that the DRM got switched to Groove DRM for some reason. It doesn't necessarily
explain why I can't download new songs though...
Unless, and I really hope this is not the case, when I booted Groove for the first time and logged in, my Zune Pass subscription automatically got updated to a Groove Pass subscription (or something like that). That might explain how all my subscription
music got its DRM suddenly changed and why I can download songs through Groove but not through Zune.
Have you ever, even once, booted the Groove music app? Did you log in? If you haven't,
DON'T, until I verify whether that is what happened.
Some time in the next couple days I'm going to boot up my old Windows 7 laptop and see if I can log into Zune and download songs there. If I can, it's a problem with the Anniversary update and I have a workaround (just can't use my main PC anymore). If
I can't I'll assume it's the Groove thing, and I'm hosed, but maybe my difficulties have saved some other Zuners from the same fate.
*****EDIT *****
Actually, it might simply have been when I logged into the windows store. I did that to download bash for windows when the anniversary update came out, and stupidly used my Zune account instead of my xbox live account. So fair warning,
if there's something you want on the windows store, don't sign in with your Zune account because it might break your DRM. Will update with results when i get around to my laptop. Probably not before the weekend.