I too started getting these errors
The specified datatype is invalid. (Exception from HRESULT: 0x8007070C)
but only for playlists. The fix, if you can call it that, was to decrypt my SD card. I'm not sure exactly when I did encrypt it, I know it was recently, but I thought I'd done a sync with MusicBee since. Perhaps not. This was happening with my Galaxy S8.