🚀 go-pugleaf

I sent a PDF document to a coworker for review. I enabled it for commenting withing Acrobat Professional 7.0. He is unable to open the document though. He gets this error: "This document contained certain rights to enable special features in Adobe Reader. The document has been changed since it was created and these rights are no longer valid. Please contact the author for the original version of this document." I e-mailed him another copy of the document to try, but he had the same problem. He forwarded my e-mail to another person, and that person was able to open the PDF on his PC just fine and was able to type comments in it. My coworker downloaded the latest version of Reader, but still did not have any luck. Is there a setting in Reader that my coworker needs to change in order to enable something within Reader? He did recently install Windows Vista; could that possibly be causing the issue?