Error Message: "Error Code 64: Host not available" Opening Views from External URL

Published: 19 Dec 2013
Last Modified Date: 05 Aug 2015


When you try to access Tableau Server views from an external URL, the following error might occur:
Session Ended by Server
An unexpected error occurred on the server. If you continue to receive this error please contact your Tableau Server Administrator.

Explanation: The Web server connection was closed.
Technical Information (for support personnel)
  • Error Code 64: Host not available
  • Background: The connection to the Web server was lost.


  • Tableau Server 8.1.0 - 8.2.2
  • Microsoft Forefront as Reverse Proxy with Threat Management Gateway Server Pack 2


Upgrade to Tableau Server 8.2.3 or a later version. For more information, see Upgrading Tableau Server in the Tableau Knowledge Base.


Microsoft Forefront Threat Management Gateway Service Pack 2 is incompatible with Tableau Server 8.1.0 - 8.2.2.
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