We apologize for your inconvenience. I have tested the issue and I’m able to reproduce the same problem. I have contacted our development team to investigate this issue in detail and they will keep you updated on the status of a correction.
I have discussed the issue with our development team, and it has been noticed that the “sst.pdf” file is damaged (which can be auto-fixed by Acrobat. Open the file and than close it with "save the change"). I am sorry to inform you that repairing the damaged Pdf files is not supported by our products, so it seems like the error is generated by Aspose.Pdf.Kit<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
I have repaired the file through Acrobat and have tried appending the sst.pdf file with pdfdoc.pdf and the resultant Pdf is opening without any error message. The file is in attachment, please take a review. In case of any concerned issues, please feel free to contact.
We apologize for your inconvenience. I have tested the issue and I’m able to reproduce the same problem. The issue is being caused by Aspose.Pdf.kit. I have logged it in our issue tracking system as PDFKITNET-5622. We will investigate this issue in detail and will keep you updated on the status of a correction
We checked the issue and found that there is a parameter-misuse in the above code.
public bool Append( StreaminputStream, StreamportStream, intstartPage, intendPage, StreamoutputStream //should not be the same stream as inputStream or portStream. );
I have tested the issue, but I am unable to reproduce the problem. I have successfully been able to append insert.pdf with output.pdf. Here I would like to share one thing, in your code snippet for PdfFileEditor.Appen, you have specified endpage argument value as 100, which should be 1, as the source file insert.pdf has only single page which is the start page and end page. Also please use following code line for output pdf.