Fix Adobe Acrobat "SigValue Is Larger Than Expected" Error
Question details
The user needs to resolve an error preventing them from completing a certificate-based digital signature in a PDF document.
- Product
- Adobe Acrobat
- Device & OS
- Windows
- Scenario
- Creating a certificate-based digital signature after adding a timestamp server to the security settings.
- Observed behavior
- Acrobat fails to sign the document and displays the error: "Creation of this signature could not be completed. SigValue is larger than expected."
Ensure you have administrative privileges on your computer to run repair installations and verify the exact version of Adobe Acrobat you are currently using.
Test Signature Without the Timestamp Server
Isolate the problem by temporarily disabling the timestamp server to see if the signature completes successfully.
A misconfigured or incompatible timestamp server can bloat the cryptographic data of the signature, causing the SigValue error.
Launch Adobe Acrobat and go to Edit > Preferences (or Acrobat > Preferences on Mac).
Select 'Signatures' from the Categories menu on the left.
Under 'Document Timestamping', click 'More'. Temporarily remove or disable the newly added timestamp server.
Attempt to apply the certificate-based digital signature to your PDF again.
Repair the Acrobat Installation
Fix corrupted or missing program files that might be causing the signature module to fail.
Upgrade to a Supported Version of Acrobat
Resolve underlying compatibility issues by upgrading from an outdated version (like Acrobat 9) to a fully supported release.
Sign PDFs Securely with WPS Office
Avoid complex configuration errors by using WPS Office to quickly and securely add certificate-based digital signatures to your PDF documents.
- 1. Open Your PDF: Launch WPS Office and open the PDF document you need to sign.
- 2. Navigate to the Protect Tab: Click on the 'Protect' tab located on the top ribbon menu.
- 3. Access Digital Signatures: Click on 'Digital Signature' or 'Sign' to open the signature manager.
- 4. Apply Your Certificate: Select your existing digital ID or certificate, place the signature box on the page, and apply it to the document.
- 5. Save the Document: Save the newly signed PDF to lock the signature and ensure its integrity.
Frequently Asked Questions
What does "SigValue is larger than expected" mean?
This error means the cryptographic data generated for your signature exceeds the allocated byte size limit for the signature field in the PDF. This is often caused by an improperly configured timestamp server bloating the file data or by outdated software handling the certificate incorrectly.
Can I sign a PDF without a timestamp server?
Yes, you can create a standard certificate-based signature using your computer's local system time. While a timestamp server provides secure third-party time verification (which is helpful for legal validity), it is not strictly required to apply a digital signature.
Is Adobe Acrobat 9 compatible with Windows 10?
No, Adobe Acrobat 9 is a legacy release and is not fully compatible with Windows 10 or Windows 11. Using it on modern operating systems can result in various security and functionality errors, including problems creating digital signatures.
