Error "No Tableau Server user found" Connecting to Data Source or Viewing Dashboard

Issue

When you try to access dashboards or send subscription emails on Tableau Server or Tableau Cloud, the following error might occur:

No server user found class DataSourceException Unable to connect to server <server name or IP address>. Check that the server is running and that access privileges to the requested database.

When you try to connect to a published data source from Tableau Desktop, the following error might occur:

com.tableausoftware.controller.dataserver.SessionController - Error response. code:401 type:DataServerNoAuth msg:No Tableau Server user found.

Environment

Tableau Server
Tableau Cloud
Tableau Desktop using Published Data Sources
Data Server

Resolution

There are two common causes for this issue. Follow the below steps as appropriate to your situation.

Cause 1: User Permissions (Tableau Server and Tableau Cloud)

If some users and some workbooks are affected, ensure that either:
The affected users have CONNECT permission to the published data source. See Capabilities you can set on data sources.
OR
The affected workbooks have credentials embedded by the publisher.

Cause 2: Forward Proxy (Tableau Server only)

If all users and all workbooks or data sources are affected, and a forward proxy server is in use, configure the proxy to ensure the exceptions in Configure for a forward proxy server are specified. Note that this configuration must be done on the primary machine and all worker machines in a distributed environment.

Cause

Cause 1: The user does not have permission to access the published data source.

Cause 2: A forward proxy is interfering with Data Server communications. All Data Server communications occur over HTTP.

Additional Information

If workbooks with embedded data sources are experiencing the issue, check that the Run-As user for Tableau Server has the correct permissionsFor more information about setting all appropriate Run As User permissions, see the following Tableau Help article: Run As User.