I had a peculiar problem yesterday. A customer put one of my Delphi apps on some Toshiba laptops, and all was fine until it was time to generate some Acrobat files as a Rave 7 report, which produced the subject error.
The laptops had Acrobat 7 Standard installed with XP SP3 and IE8. I uninstalled Acrobat 7 Standard, put in Acrobat 5 Reader which they had lying around, and the problem went away. However, the customer doesn't see backtracking Acrobat as a solution, because the usual environment this Delphi app runs in of XP SP3, IE 7, and Acrobat 7 Standard doesn't show this problem.
A Google search didn't reveal any recent causes or effects. The Microsoft and Adobe KBs deny that any problem exists.
Any clues as to what specific area needs a workaround? Today I'm going to uninstall IE8 and reinstall IE7.
I came a cross the same problem, in IE with the Adobe ActiveX plug-in. It was some time ago, but if I remember correctly the problem was the ActiveX in some versions of Acrobat 7, maybe combined with specific versions of the PDF itself. Installing the latest Adobe Reader solved the problem.
If reinstalling Firefox (or your browser) and reinstalling Adobe Acrobat Reader does not work is because it is inheriting settings from past versions. What worked for me is doing a manual uninstall of all stored application data. In Win 7 Go to C:/users/your name/AppData/Roaming/Mozilla or Microsoft/ and the try to delete all of the content related to your browser including extensions and plugins. If you don't have permission to delete folders then open it and delete file by file.
Note that you have to be able to view hidden files to access AppData folder. Then do the same for the AppData under Adobe folder. Then reinstall Firefox and acrobat reader. Done!
PDF files are suppose to start with the sequence "%PDF-X.Y"; however, some programs, email programs are notorious, will add a header, such as Mac Binary. Acrobat looks in the first 1024 bytes for the %PDF sequence. Other applications only support %PDF at the beginning of the file.
We were experiencing this and found that it was a matter of adding the site to the "allowed popups" list.