OK - so - this is not really a fix - but more of a workaround..
I get audio files from an internal company site that sends the files in .mp2 format. In the past I have used this program to convert them to .mp3. For some reason, the files are now received as .wav files and when I try to convert those I get that BS codec error.
So - the stupid thing - if I rename the file (change extension) to .mp2 - Switch will then convert to .mp3 and it sounds fine..
That's what I'll be doing until the really smart guys come up with a fix..