Hey everyone,

So I've finally upgraded from 8.1 to 10, and it seems the anniversary update broke the conversion feature, according to reddit. Lots of people are suggesting converting files outside of the Zune software or downgrading their OS to continue using their Zunes. I found what I think is a solution (until Microsoft breaks it further). Note that I've only tested this on MP3 and not video files.

The conversion relies on Windows Media Player Codecs which have been apparently removed from Win 10 Anniversary. So to fix it, I closed the Zune software, launched Windows Media Player, and completed the WMP setup process. Close Windows Media Player, re-launch the Zune software, and suddenly your files will convert again. Something about completing the setup of Windows Media Player put those codecs back where they needed to be. Odd indeed, but I hope this is helpful. Cheers!