Problem

JACE shows "Authentication Error" when trying to connect back to Supervisor via Niagara Network. Supervisor can reach JACE (green connection), but JACE cannot reach Supervisor (red fault). Scheduling and remote commands fail.

Root Cause

The Niagara Network is bidirectional—each side initiates a separate connection. The error indicates the JACE credentials (username/password or certificate) are incorrect or have expired on the Supervisor side.

Solution

1. On the JACE station, navigate to the platform Niagara Network settings where the Supervisor connection is defined

2. Verify the username and password used for the Supervisor connection are correct

3. If unsure of the password:

   • Re-enter it by editing the platform connection on the JACE
   • Use the same credentials configured on the Supervisor for that user

4. For certificate-based authentication:

   • In Workbench Certificate Manager on JACE, check the Allowed Hosts tab for the Supervisor certificate
   • If it has a red X, try deleting the approved cert, forcing the connection error, then re-approving the newly created cert

5. Restart the platform connection (or entire JACE if needed)

6. Test by running a simple schedule push from the Supervisor—if it succeeds, authentication is restored