You are here: Administrator's Guide > Securing FME Server > Connecting to Active Directory > Troubleshooting Active Directory Configurations > Single Sign-On Authentication Failure (Same Machine Access)
Log file messages:
(Single Sign-On) Negotiation reported a defective token from client: "Defective token detected (Mechanism level: GSSHeader did not find the right tag)".
(Single Sign-On) Failed authentication because of an negotiation error. Refer to single sign-on documentation for resolution.
Cause
Single sign-on authentication was attempted on the same machine as FME Server.
Resolution
Use a different machine to access FME Server.