Error "Tableau Data Engine Error: 406" or "Tableau Data Engine Error: 40688" Connecting to Excel

Published: 29 Sep 2016
Last Modified Date: 15 Jul 2020


When connecting to an Excel data source, one of the following errors occurs:

Tableau Data Engine Error: 406:Unable to connect to the file. Check that the file exists and that you have sufficient access privileges for it.


Tableau Data Engine Error: 40688: typefactory::nametype key


  • Tableau Desktop 
  • Windows 10
  • Excel


Option 1

  1. Open Tableau Desktop with administrator privileges by right-clicking on the icon for Tableau Desktop and selecting 'Run as administrator'. Then, attempt to connect again to the Excel file
  2. If selecting Run as Administrator does not resolve the issue, completely uninstall and reinstall Tableau Desktop. Then, open Tableau Desktop with the 'Run as administrator option' selected.
Note: See the Knowledge Base article, Completely Removing Tableau Desktop, for information on how to completely remove Tableau Desktop

Option 2

Work with your IT team to ensure that your user account has administrator rights or security permissions to the AppData folder.  

Option 3

Work with your IT team to allowlist the temporary files folder in anti-virus or firewall programs that are in use. 


Either your user account does not have the necessary permissions to access the file, or antivirus is interfering with the connection. 
Did this article resolve the issue?