Error: Invalid pdf format:pdf head signature is not found!

We are combining multiple documents into one PDF so that we can print them all at one time using Adobe Reader. We are using this on our production server and have executed it approximately 6,000 times now receive the above error on one "package" of documents.

I can load each of the 22 documents one at a time with Reader and they all load successfully so I don't believe there is a problem with one of them. All documents are loaded into an array of streams and then combined into one. The error occurs at the the last line in:

' Instantiate Aspose PdfFileEditor object

Dim pdfEditor As PdfFileEditor = New PdfFileEditor

' Aspose method to concatenate all input streams -

pdfEditor.Concatenate(inStreams, outStream)

I saw an old thread about this error but it said a hotfix had been issued last year. We installed the product on February 1, 2008 and the DLL is dated 12/29/2007. Shouldn't this DLL contain the fix or should I load the hotfix now to see if that will solve the problem?

Thanks, John

Hi,

The latest version of the dll contains all previous hotfixes. The cause of the problem in your case is probably some thing else. Can you please provide us with your complete code and the input pdf files so that we can test this issue. Please refer to following article:

How to Share a Document in a Forum Post

Thanks.