File Does Not Begin With '%PDF-'
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.
Answer
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.