Concatenating PDF

After concatenating 2 pdf's using PdfCopyFields, I am able 开发者_StackOverflow社区to edit the PDF fields, but I can't save the merged PDF. Why am I not able to save the PDF after doing this?

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A form that has been Reader Enabled must be saved in append mode in order to continue working as such. PdfCopyFields creates a new PDF from scratch.

To get this working, you'll have to duplicate most of PdfCopyField's code via a PdfStamper set to append. Hurray for open source.

And keep in mind that iText 5.x is AGPL. Anyone with access to the program output must also have access to the source.

(which is why quite a few people are still using 2.1.7)