As the message indicates, the Reader rights that can be enabled by Acrobat Pro are local save and digital signatures. Acrobat Pro does not enable rights to be added for commenting or attachments.
Well, it's a bit more complex.
Acrobat Pro does allow forms to be reader extended for commenting. In fact, the rights include form fillin and save, creation and modification of form fields (including adding digital signtures), applying a digital signature and adding comments. But there are two other things that can be getting you:
- You can't put comments on a dynamic form... only static or pdf artwork
- You can attach files to a PDF in one of two ways. The first is an attached file in a comment. The second is as an embedded/attached file (this is the file support that is now called portfolios). There is a Reader Extension right called "additions and changes to embedded files" that is needed for this. It is only available through the server-based Reader Extensions and not in Acrobat.
Chuck is correct. My mistake. I am accustomed to saving dynamic forms and I overlooked the impact upon Reader Extensions.