3 Replies Latest reply on Nov 12, 2018 7:18 AM by Egor Larin

    System Error: Null

    Martin Sellers

      I am getting this error message when using the center output.  "system error: null"

      This flow was working previously.  I updated a few of the early steps and added the union.  Since then I have been getting the error.


      To get around this, I right clicked the step before my output and chose to "preview in tableau" and the data exported to tableau fine.   I then exported the data to csv from Tableau to continue my work.

      The other two outputs in the flow seem to work fine.


      Any idea what's going on?


        • 1. Re: System Error: Null
          Michael Enck

          I often get this error when the Tableau Desktop file is still open.

          • 2. Re: System Error: Null
            Rob Palmer

            I've been having the same error. However, if I tell it to publish directly to Tableau server it works fine. Just seems to be exports to disk that are causing it.

            • 3. Re: System Error: Null
              Egor Larin

              I have the similar issue.


              Do you have any STR to INT or INT to STR transformation?


              I found if you use  field that was transformed to STR (original field is INT) in JOINS output just after JOIN stopped working.

              After removing INT->STR transformation -  the whole flow is started working.


              Try to define on which step you have failing output. Basically, you can run output from any 'block' to troubleshoot it:



              Found that issue here:

              Prep: System error: null


              And issue #783920 from the Release Notes. Not sure if that relates to the issue.

              After joining a .csv file with a MySQL table, the following error occurred, when publishing the .hyper file to Tableau Online/Tableau Server:

              "Collation mismatch, use COLLATE statements to resolve."


              In the logs I can see the errors:

              com.tableau.loom.exceptions.OutputNodeFailureException: Unable to process output step: Failure evaluating to database: ERROR:  collation mismatch, use COLLATE statements to resolve


              TID:pool-3-thread-4 DOC_ID:888fdaaf-ca04-4cc6-8cb5-5407fb087466 REQ_ID:43a9d1f8-9770-4287-8a31-ddbf2b1accef LVL:ERROR CLASS:com.tableau.loom.runtime.SelectIntoExecutor MSG:Error processing selectInto