I unable validate the signature and it throws an error.... Certification by xxxxxxx invalid.... Can you please help with this? I tried to validate in different PC but issue remains same.
Attached error screenshot below.
Hope you are doing well and sorry for the trouble. As described the signature in the PDF is showing invalid.
Is this an issue with a particular PDF file or with all the PDFs with digital signature? Please try with a different file and check.
Would you mind sharing the version of the Adobe Acrobat Reader DC you are using? To check the version go to Help > About Acrobat and make sure you have the latest version installed. Go to Help > Check for updates and reboot the computer once.
Also, try to reset the Acrobat preferences as described in the help page https://community.adobe.com/t5/acrobat-discussions/how-to-reset-acrobat-preference-settings-to-defau... and see if that helps.
For more information about validating the digital signatures please check the help page https://helpx.adobe.com/acrobat/using/validating-digital-signatures.html
Thank you for sharing the information. Is this a behavior with a particular PDF file with signature or with all the PDFs?
Please try the other suggestions shared earlier and see if that helps.