iText Suite version 9.0 introduces a brand-new major version of the iText Core library, and updated Core add-ons. We've finalized the dedicated PDF digital signature validation module, and added support for the ISO/TS 32003 and 32004 standards. Not only that, but we also have new and improved APIs and much, much more.

PDF generation from HTML templates is a common iText use case and is especially useful for the creation of documents which must conform to the PDF/A and PDF/UA standards for archiving and accessibility. This article compares how you would create PDF/A documents with iText 5, and the improved methods available in iText version 8 with the pdfHTML add-on.

The ability to apply and validate secure PDF digital signatures has long been a particular strength of the open-source iText Core library. We’ve kept pace with advances such as support for PAdES and PDF 2.0, and so we’re proud to present a guest blog detailing iText 8’s support for the latest ISO extension standards for digital signing.

If you’ve ever encountered this error when opening or validating a PDF with iText 5 and earlier versions, then this article is for you! We’ll explore what this error message means, the reasons why you might encounter it, and the ways you can resolve it.