Invalid Digital Signatures in Forms

If the digital signature of a form is invalid, this is usually caused by one of the following:

• The signature has been invalidated by changes to the form, such as changes to texts or layout.

  Caution

  Adobe Reader displays the signature as invalid if changes have been made to the form data. A checkmark and exclamation mark appear with information that the document has been changed.

• The certificate for the signature is invalid. The same conditions apply as for an invalid certification.

  More information: Invalid Certification of a Form