Error "An error occurred while communicating with the data source" Connecting to Oracle

Published: 15 Mar 2017
Last Modified Date: 20 Oct 2020


When trying to connect to Oracle, the following error may occur: 
An error occurred while communicating with the data source
Bad Connection: Tableau could not connect to the data source.
No details available.

Errors similar to the following can be found in the tabprotosrv logs:
  • Cannot load library from preferred location, "C:\Program Files\Tableau\Tableau <version>\bin\\<path>\ORAHOME\bin\oci.dll", since it doesn't exist.
  • Unable to load library "\\<path>\ORAHOME\bin\oci.dll" (error 87)


  • Tableau Desktop
  • Windows
  • Oracle


Try one of the following:
  • Remove the ORACLE_HOME environment variable if it is not used by another process, or edit the PATH variable to match that of another user who can connect successfully to Oracle.
  • Copy the oraociei12.dll from  C:\Program Files\Tableau\Tableau <version>\bin to the directory indicated by the ORACLE_HOME environment variable.


Tableau is unable to locate the correct Oracle driver.
Did this article resolve the issue?