Issue

When activating/deactivating Tableau Server, the prompt "Online Activation Unavailable" will appear and request to "Activate License Offline".

Environment

Tableau Server 2021.1 and later versions
Linux OS
Forward Proxy/Load Balancer with SSL Inspection

Resolution

Workarounds

Option 1: Disable SSL Inspection

By disabling SSL inspection, the appropriate certificates will be presented to Tableau Server allowing for the SSL handshake to complete.

Option 2: Bypass the proxy for licensing.tableau.com

An exception can be granted to calls heading toward licensing.tableau.com:443 so that requests headed to our Tableau licensing servers will not have its SSL certificates intercepted and modified.

Cause

Tableau Server is unable to validate certificates presented from the Proxy/Load Balancer configurations that performs SSL Inspection.

Additional Information

The Tabadmincontroller log will display the following error message:

ERROR com.tableausoftware.tabadmin.webapp.GlobalExceptionHandler - RestException: Licensing Error: Licensing Service Unavailable
com.tableausoftware.tabadmin.webapp.exceptions.RestException: com.tableausoftware.license.dll.ConnectException: Function flxActSvrReturnSend returned error (50041, 41143, 34) LM_TS_CONNECTION_FAILED
Tableau could not connect to the licensing server or FlexNet Operations Server. Verify the product key is correct and the primary or online licensing server can be accessed by ports 27000-27009.

A network capture may display the following "Unknown CA" alert during the SSL handshake to Tableau's licensing servers: