"Invalid xref type" when resaving existing PDF

When I use Aspose.PDF to open the attached file, and then immediately try to resave it, an exception with the message "Invalid xref type" is thrown. As far as I can tell, the file isn't corrupted - Acrobat's analysis tools seem to be fine with the file (I'm no expert on using those, though). Is there something that can be done to successfully rewrite the file? We need to be able to open it, make a few changes, and resave it. We are currently using Aspose.PDF Version 9.7.0.0.

Thanks,
Michael Whalen