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Illegal Filter Mode Exception in PdfFileStamp


I get an error applying an Stamp on an Pdf document:

System.SystemException: Illegal filter Mode.: v4.9.0.0
at xeb116a323308e2f7.x7759a935a2782a02.xb9fd793f310cc289(x3cb3e02ca07b8735 xcf18e5243f8d5fd3, x847acb1842aef4c9 xb44380e048627945)
at xeb116a323308e2f7.x7759a935a2782a02.xb9fd793f310cc289(x3cb3e02ca07b8735 xcf18e5243f8d5fd3)
at xeb116a323308e2f7.xe923a3ea50a7237f.xeb1688f3c25edfc6(x1ac4f595ab61cbe1 x4b18414d8aa2b78b)
at xeb116a323308e2f7.x3233d061fc77cddd.close()
at Aspose.Pdf.Kit.PdfFileStamp.Close()

What does this mean?

I get this error with some pdf documents in the production environment. Other pdfs make no problem.
In our test environment the processing is correct with the same pdf causing problems in production!

What are possible causes?

The code snipplet:

fileStamp = new PdfFileStamp(inStream, outStream);

Stamp logoStamp = new Stamp();
logoStamp.BindLogo(new FormattedText(replacedText, new FontColor((byte)R, (byte)G, (byte)B), fontStyle, EncodingType.Winansi, true, (float)TextSize));
logoStamp.SetOrigin((float)PosX, (float)PosY);
logoStamp.IsBackground = false;
logoStamp.PageNumber = i;


Thank you,
Best regards,


Hi Jan,

First off, please try to use the latest version at your end and see if it resolves your issue. However, if it still doesn’t resolve your issue then please share the input PDF file with us. Also, please share the details of the environment where it fails i.e. OS, .NET Framework version, application type (Web, Windows, Service etc.). We’ll investigate the issue at our end and guide you accordingly.

We’re sorry for the inconvenience.

Hi Shahzad,

I already tried the latest version...

As this is not the first problematic error (pages were mixed up in pdf concatenation), we decided to switch to PDFlib.

Thanks anyway,

Best regards,


Hi Jan

I’m very sorry for the inconvenience. Actually, if you could share the sample input file along with the details of your working environment, we would be able to investigate and provide a fix for this issue.

However, if you need any further assistance from our side, please do let us know.