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Participant
October 26, 2020
Question

Unable to Digitally sign a PDF document

  • October 26, 2020
  • 1 reply
  • 477 views

Hi I have a colleague who is unable to digitally sign only one signature out of many signatures.

She is getting an error "The validity of the document certification is UNKNOWN". The author could not be verified. Signed and all signatures are valid".  I tried all the steps I found on Google (Adobe community) but was unable to resolve it . Please let me know what other details are required so that you can help me to resolve it

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1 reply

Karl Heinz  Kremer
Community Expert
Community Expert
October 26, 2020

Is it possible that the signature is a "self signed signature" and not from a known certification authority (CA)? If so, Acrobat (or any software that can work with digital certificates) will not be able to verify that the signature is valid. You would have to export the public key from the signature owner and import it into the computer on which you want to validate the signature. 

Sujit5E59Author
Participant
October 26, 2020

Thank you very much for your email Karl. However, I have a question why I am able to digitally sign all the signatures on my laptop. She tried to digitally sign that document on another laptop and it worked there as well. It is causing issue only in one laptop.