Unable to Connect to Oracle When Essbase Driver is Installed

Published: 11 Jun 2021
Last Modified Date: 14 Jun 2021


After installing both the Oracle OCI and Essbase drivers for Tableau Desktop 2020.4, when connecting to Oracle in Tableau Desktop, the following error may occur:

An error occurred while communicating with Oracle
Bad Connection: Tableau could not connect to the data source
Error Code: 383490FC
Unable to connect to the Oracle server '
<server>. Check that the server is running and that you have access privileges to the requested database.


  • Tableau Desktop 2020.4
  • Oracle
  • Windows


Try the following workarounds:

Option 1

Copy the attached oci.dll file to C:\Program Files\Tableau\Tableau 2020.4\bin and overwrite the oci.dll file in that folder.

Option 2

  1. Delete the oci.dll file in C:\Program Files\Tableau\Tableau 2020.4\bin
  2. Navigate to Control Panel\Programs\Programs and Features, right-click on the Tableau 2020.4 Oracle Driver in the list of programs, and select Repair.
  3. In the User Account Control dialog that appears, select Yes.


This issue is currently under investigation.
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