Have you saved it as a SEQ file first?

RB will try to handle BiaB files like BiaB (ie generate the whole track, generate the whole song when Generate is hit, etc) which *may be contributing to your issue.
Try saving as SEQ file and see if it works better.

What is the 'dreaded RB error' you get?
Can you post it? That can help a lot, especially if support sees it.

Also, I use the 'Make all BB tracks regular tracks' in RB, so they start acting more like a DAW, and this seems like something that is more of a DAW feature, so maybe try that too (using Save As for this change so you don't lose work afterwards).
It's a right-click -> Tracks feature from memory.

Make your sound your own!
.. I do not work here, but the benefits are still awesome