[Zubersoft]

Without knowing more details, that seems like some kind of unrecoverable error is occurring during the export. Normally I would ask for you to export the piece, but seeing as how that isn't possible, the only other way for me to try to reproduce the issue would be a full library backup file. Let me know if you want to upload that for me to test, otherwise I'll need a lot more information about the piece, and you may have to try removing things from the piece until it exports successfully so we can identify what is the problem. One thing you can try doing is uncheck the option to export annotations and see if that is successful. If so, we know the problem is related to the annotations in the score.

Mike