Unable to open accessibility report attachment

When I create 508 compliant PDFs, I have Adobe add the report as an attachment to the PDF. When I try to open the attachment from within the PDF, it just opens a blank HTML page.

If I have Adobe create the report outside of the PDF, so it's sitting in a folder rather than attached to the PDF, it opens fine. However, if I attach that same report to the PDF, it no longer opens. Once again, I get a blank HTML page.

Does anybody have any idea why this is happening or how to fix it? I'm using Adobe Acrobat Pro XI.

Thanks!