Combining Multiple PDFs Using PDFSharp
Answer : I have come to believe that it might be the input PDFs that are corrupt or unreadable to PDFSharp. There are several examples of SSRS PDFs not being readable to PDF-libraries or even Adobe's Reader. For example here: http://www.sqldev.org/sql-server-reporting-services/export-pdf-in-ssrs-2008-vs-ssrs-2005--pdf-is-different-wont-work-with-itextsharp-possibly-other-13968.shtml ... and here: https://stackoverflow.com/questions/2393175/ssrs-2008-pdf-files-cannot-be-opened ... AND most importantly on the PDFSharp forum: http://forum.pdfsharp.net/viewtopic.php?f=2&t=674 I don't know if this is the bug you're encountering - the message is strange - but it seems likely to have something to do with that, when you take in to consideration that your code sample works flawlessly with any PDF I tried (I don't have any SQL Server Reports to try out, though) I don't sure about my answer. Please read your self. http://www.go4coding.com/post/2011/05/26/...