Error "Invalid field formula" When Appending to Data Source

Published: 23 Jan 2015
Last Modified Date: 04 Mar 2018


When appending data from file or data source to an existing extract, the following error message might occur:
Unable to append data from file.
Invalid field formula due to limitations in the data source.
Unable to create extract


  • Tableau Desktop
  • Excel or Text files


  1. Right-click the data source and switch back to a live connection.
  2. Locate any fields which had their data types changed within the workbook following the initial creation of the extract.
  3. Right-click the field(s) and change the data type (e.g., from a String to a Number).
  4. Right-click the data source and re-create the extract.
  5. Then, append data from your new file.


The data type definition for a field used in a calculation differs between the extract and the workbook. Data type changes made in a Tableau workbook do not apply to an existing Tableau Data Extract.
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