Troubleshooting Smart Card Logon on Active Directory
Diagnose and resolve smart card logon failures in Windows Active Directory environments — error messages, revocation checks, certificate mapping and more.
Error Messages
Detailed cause and resolution for each Windows smart card logon error: certificate not trusted, credentials could not be verified, KDC errors, no valid certificates found, and more.
Checking Smart Card Health
Use certutil -scinfo to diagnose the smart card state: absent card, missing minidriver or CSP, service not running, and how to verify a certificate can be used for logon.
CRL Troubleshooting
Verify certificate revocation checks, solve CRL network and proxy issues, clear the CRL cache for testing, and disable CRL checks when no CDP is available.
Certificate Mapping
Determine the mapping type (UPN vs explicit), identify and fix mapping mismatches, handle KB5014754 changes, and understand available altSecurityIdentities formats.
Annex — Procedures
Step-by-step procedures: exporting a certificate chain, adding a root CA certificate to the NTAuth (NTLM) store via the PKI Health Tool or certutil.