Konica Minolta IEEE 802.1X Error 20
The printer could not validate the EAP server certificate back to a trusted certificate authority.
Error meaning
CA verification of the EAP server certificate failed.
This meaning is tied to the reviewed family/platform and subsystem below; do not reuse the number or wording by itself on a different printer family or protocol.
Applies to
bizhub C287/C227
- bizhub C287
- bizhub C227
Common formatting
These are formatting/lookup aliases for this reviewed condition, not separate error pages.
- 20
- ieee8021x-20
What usually causes it
- The required root or intermediate CA certificate is missing from the printer's trust store.
- The RADIUS server is presenting an incomplete or newly changed certificate chain.
- The installed CA certificate is wrong, expired, or no longer matches the issuing chain used by the server.
What to try
Identify the CA chain used by the authentication server
Ask the administrator which root and intermediate certificates should validate the current RADIUS certificate.
Check the printer's trusted CA certificates
Confirm the required CA material is installed and valid on the C287/C227.
Check the server's presented chain
A correct printer trust store can still fail if the server omits a needed intermediate certificate.
Reconnect after trust is repaired
Install or correct only the required trust material, then retry. Do not disable CA verification as a shortcut.
After each corrective action
Retry the same operation that produced 20. If it now works, stop there rather than changing unrelated printer, network, supply, or service settings.
If the code returns
If code 20 persists, compare the exact server certificate chain with the CA certificates installed on the printer and verify that no old CA remains selected.
When service may be needed
This is a certificate-chain trust problem. Use the network/security administrator or Konica Minolta support rather than weakening certificate validation.
Continue with guided troubleshooting
If the printer still is not working after the reviewed checks, carry this verified error context into the guided troubleshooter.
Related information
Verified source
Official Konica Minolta product-family user guide. Candidate meanings are paraphrased from protocol-specific code tables; manufacturer prose must not be copied into public pages.