Troubleshoot common digital signature issues
Troubleshoot common issues you might encounter when setting up digital signatures.
- Can I modify a document after it is digitally signed?
- The produced digital signature isn’t valid, and the validation status says “the document has been tampered with”
- The validation status of a digital signature says that “at least one signature has problems”
Common mistakes
| Mistake | Symptom | Fix |
|---|---|---|
| Using a self-signed certificate in production | Yellow warning bar in Adobe Reader | Use an AATL-trusted certificate |
| Missing certificate chain | “Certificate chain not valid” error | Include intermediate certificates in signing response |
| Wrong signature format (PKCS#1 vs PKCS#7) | “Invalid signature” after signing | Check your HSM/signing service output format matches SDK expectations |
| Signing already-signed document without incremental save | Previous signatures invalidated | Use incremental saving mode |
| Certificate expired | Signature shows as invalid | Renew certificate before expiry |