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.

In this latest release, Core will open documents faster and be more resilient to malformed PDFs. We’ve also widened its support of CCITT-compressed TIFFs, and improved the paragraph text wrapping. There’s also support for the CSS vertical-align property in pdfHTML, and improvements and bugfixes across the rest of the Suite.