Hi Dionin. I'm also getting similar errors if I save a song to MIDI (or indeed to a WAV) - even if I run as Administrator. However, this only occurs if I have "Frozen" tracks in my song. So the workaround for that so far is to unfreeze any frozen tracks.

Good to hear that you're up and running now!

I have BIAB installed to c:\BB

I might try the VSTi version of Sampletank - since that seems to do the trick - and yes I was getting the registry error too if I didn't run BIAB as Administrator.