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Common Errors & Solutions

Apr 5, 2026 · 468 views

Quick fixes for the errors we see most in support tickets, grouped by area.

API & Authentication

401 "Access Denied"

Cause: missing or wrong token. Fix: send Authorization: Bearer YOUR_TOKEN; compare with the token in the General/Tenants tab. After changing tokens, POST /api/reload-config or restart the service.

"Port already in use"

Fix: find the conflict with netstat -ano | findstr :9440, then change either the other app or OneSigner's port (General tab).

403 on code signing

Cause: a certificate thumbprint allowlist is active (thumbprint-locked license or AKV allowlist) and the certificate being used is not on it. Fix: sign with the licensed certificate, configure the profile to select by SHA1 thumbprint, or use a license without an allowlist. See License & Signing Security.

Licensing

"License expired" / "DemoExpired"

Fix: the trial ended — purchase a license and paste the key in the License tab. Configuration is preserved.

"Feature not available in current license"

Fix: the feature (e.g. multi-tenant) is not in your plan — see plan comparison or contact support to upgrade.

"Hardware ID mismatch"

Fix: the license is bound to another machine. Contact support@onesign.sg to transfer it.

"CRL check failed"

Fix: allow outbound HTTPS to onesign.sg. A 7-day grace period covers temporary outages, so signing does not stop instantly.

Signing

Files sit in the source folder unsigned

  1. GET /api/signing/status — engine enabled? any lastError?
  2. Profile switched On, and the file extension matches the profile type?
  3. Source folder path correct (watch out for renamed shares)?
  4. Interactive user session active? (Session 0 guide)
  5. Check the portal Logs page and Windows Event Viewer → Application.

"File is locked" during signing

Fix: another process still holds the file. OneSigner retries automatically (up to 10 times); make sure the producer closes files after writing, and don't open watched files in a viewer.

Timestamp errors on code signing

Fix: the TSA is unreachable or throttling. Try another server (http://timestamp.digicert.com, http://ts.ssl.com, http://timestamp.sectigo.com) and retry — timestamps are worth the retry, never disable them.

eSign Portal

Signer emails not arriving

Fix: configure SMTP (Settings → Email) and check spam; verify SPF/DKIM for your From domain. Until SMTP works, use the copy-link button per signer.

Signing link says it's not the signer's turn

Expected: signers are sequential — the link activates when the previous signer completes.

Bridge shows "not connected" on the signing page

Fix: OneSignerBridge must be running on the signer's machine with the token plugged in; reload the page. See Visual Signing troubleshooting.

Not listed? Open a ticket from the Support page with the error text and the portal Logs entry.