PARTIAL SOLUTION - Thank God - I don't know why this is - PGMusic might want to look at it - - - I was finally able to save my .SGU file - BUT -now it will only save to the BIAB folder. It will not save to the Desktop. It will not save to the peripheral drive, it will not save to the "HD" (Hard Drive) - it will only go into the BIAB folder.
How about if you create a folder on your root HD like \testsongs and try to save the file in there, what happens then?
The error message does come from Band-in-a-Box so it's not surprising that Google / Apple doesn't address that exact message.
But it should only occur if indeed you are saving to the root HD, and I don't know why it would otherwise come up. Maybe the answer to the above question will shed some light.