How to resolve “At least one signature has problems.” error in Adobe Reader?
January 13, 2014
Adobe Reader is used to open PDF documents. The PDF documents may be encrypted for security. And also PDF documents may be digitally signed for authentication. When there is any digital signature required to authenticate the PDF documents are not available on your system or the signature has the problems, Adobe Reader fails to authenticate the document, will display “At least one signature has problems” message. Below steps explains how to resolve this issue.
Step 1. Open your PDF document in Adobe Reader application. If there is a signature problem with the document, it will show the message “At least one signature has problems” message.
Step 2. Click on “Signature Panel” button which will be on right of the message.
Step 3. Click on Validate All link. It will prompt the message to validate all signatures depending on the settings.
Step 4. Click on OK button to validate all the signatures. Once all the signatures are validated it will show success message depending on the settings.
Step 5. If the signatures are successfully validated; Adobe Reader, will show the “Signed and all signatures are valid.” message. Then, you can skip the next steps.
If you are still seeing “At least one signature has problems”, proceed with the next steps.
Step 6. Select the signature which has the problem and right click on it. It will display a pull-down menu.
Select “Show Signature Properties…” menu item. It will display Signature Properties window.
Step 7. Click on “Show Certificate…” button. It will open Certificate Viewer window to view the details of a certificate.
Step 8. From Certificate Viewer window, click on Trust tab. It will display “Trust Settings” and “This certificate is not trusted” message.
Step 9. If you received the PDF document from trusted source or the certificate is from trusted source, click on “Add to Trusted Identities…” button. Otherwise, skip here and don’t validate your signatures.
Step 10. Adobe Reader, will prompt you a message “Trusting certificates directly from a document is usually unwise. Are you sure you want to do this?”. Click on OK button if you trust the source. Otherwise, stop to continue to next steps.
Step 11. Now it will display “Import Contact Setting” window. Select “Use this certificate as a trusted root“ check box and click on OK button to import contact settings into your system.
Step 12. Now the signature is validated and it will display Signature is VALID, signed by message in Signature Properties window which is opened in Step 6.
Step 13. Click on Close button to close Signature Properties window.
Now the signature is trusted and validated. Once it is validated it will display “Signed and all signatures are valid.” message. Now the PDF document is validated.