Prep Flow Fails With "Error "System Error: An Error Occurred While Communicating With The Data Source No Such Column" using 2023.3

Published: 11 Dec 2023
Last Modified Date: 22 Feb 2024


When running a flow with multiple connections and a union that also has an aggregate step, the following error may occur:

System error: An error occurred while communicating with the data source. No such column.

The issue does not occur on Tableau Prep Builder versions earlier than 2023.3 and the same flow previously worked on an earlier version if you recently upgraded.

The same error can occur on flows published to Tableau Cloud.



  • Tableau Prep Builder 2023.3 or newer


Thisis a Known Issue W-14621783 that is fixed in Tableau Prep Builder 2023.3.1.
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