Supported file types are AAC, AMR, MP3, WAV, WMA, AAC+, and MIDI. When manually adding the device as a handheld no types are specified, so I add mp3 as the only supported file type so that my flac files should convert to mp3.
The device does show up in windows as a removable storage device and files can be added by dragging and dropping.
I am currently using 16.0.149 I will update and see if that helps anything. EDIT: checking for updates gives this error: "There was a problem checking for updates." What kind of problem could there be? I'm connected to the internet and my firewall isn't blocking MC.
EDIT: OK I solved the problem, I don't know what the issue was, but completely uninstalling MC and reinstalling the latest update seems to have fixed it as well as some other issues I was having. Sorry, I guess that means the problem was on my end all along.