How to Know a PDF is Corrupt

Open a PDF in Adobe Acrobat DC.  Then without doing anything else, close the PDF. Does Acrobat ask to save changes even though you made no changes? If so, then it means that Acrobat auto-fixed a corrupt PDF.

Validating PDF Signatures with

A Chilkat customer is signing PDFs and then validating using the online tool at A few errors/warnings were encountered: 1) “The signature is not intact”.   <b>This error only happens if the “ltvOcsp” option was set</b> to create an LTV-enabled signature.  The source of the “Signature is not intact” error can be found here: When “ltvOcsp” is specified (i.e. […]