Fix The Credential Selected for Signing Is Invalid in Acrobat
Question details
Users encounter an invalid credential error when attempting to apply digital signatures to PDFs.
- Product
- Adobe Acrobat
- Device & OS
- Windows
- Scenario
- Applying a digital signature to a PDF document in an environment that uses self-signed certificates and a recently changed root certificate.
- Observed behavior
- Acrobat displays the error message 'The Credential Selected for Signing Is Invalid', blocking the application of the digital signature.
Ensure your Windows system date and time are perfectly accurate, as an incorrect system clock can cause valid certificates to appear expired or not yet valid.
Verify and Update the Windows Certificate Chain
Ensure the signing certificate is valid, possesses an accessible private key, and correctly links to the newly deployed root certificate.
When an environment updates its root certificates, old user certificates or duplicate intermediate certificates can break the trust chain. Cleaning up obsolete certificates and verifying the path often resolves signature validation failures.
Press the Windows key + R, type 'certmgr.msc' into the Run dialog, and press Enter to launch the Certificate Manager.
In the left pane, navigate to Personal > Certificates. Find the specific certificate you use to digitally sign PDFs.
Double-click the certificate. On the 'General' tab, ensure it says 'You have a private key that corresponds to this certificate'. Then, go to the 'Certification Path' tab to ensure the chain leads to the new root certificate without errors.
If you notice duplicate or expired certificates referencing the old root certificate in your Personal store, right-click and delete them. Restart your computer and Acrobat to refresh the certificate store.
Enable Acrobat to Trust the Windows Certificate Store
Configure Adobe Acrobat to rely on the Windows certificate store so it recognizes your organization's self-signed root certificate.
Easily Digitally Sign Your PDF Documents with WPS Office
Bypass complex certificate validation errors by using WPS Office to quickly, securely, and intuitively apply digital signatures to any PDF file.
- 1. Open Your PDF in WPS: Launch WPS Office and open your PDF document utilizing the built-in WPS PDF reader.
- 2. Access the Protect Tab: Click on the 'Protect' tab located on the top navigation ribbon.
- 3. Select the Signature Tool: Click on 'Sign Document' or 'PDF Signature' to bring up the signature manager.
- 4. Apply Your Digital Signature: Choose your digital certificate from the list, draw your signature area on the document, and securely save the signed PDF.
Frequently Asked Questions
Why did my digital signature suddenly become invalid?
This typically occurs if the root certificate used to issue your personal certificate was changed, updated, or expired. Your system and Acrobat need the newly updated root certificate in their trusted stores to successfully validate your digital signature.
How do I know if my private key is accessible?
Open the Windows Certificate Manager (certmgr.msc), double-click your personal signing certificate, and look at the General tab. You should see a small key icon alongside the text 'You have a private key that corresponds to this certificate'.
Can an incorrect computer clock cause certificate errors?
Yes. If your computer's date and time are significantly out of sync with reality, a valid certificate might be evaluated by the system as expired or not yet active, immediately resulting in an 'Invalid Credential' error.
What is a self-signed root certificate?
A self-signed certificate is generated and signed by the organization or individual using it, rather than a publicly trusted Certificate Authority (CA). Because it isn't verified by a public CA, client devices must manually have this root certificate added to their trusted store to avoid security warnings.
