Client software failed to load. Be sure the database client software is installed and configured correctly

Error Message

When attempting to connect to an Oracle database from an ArcGIS application, the following error occurs:

"Client software failed to load. Be sure the database client software is installed and configured correctly."

Cause

This error may occur for the following reasons:

• No Oracle client is installed on the ArcGIS for Desktop machine
• Only the 64-bit client is installed when attempting to connect to Oracle from ArcMap or ArcCatalog, which are 32-bit applications
• Only the 32-bit client is installed when attempting to connect to Oracle from ArcGIS for Server or ArcGIS Pro, which are 64-bit applications.

Solution or Workaround

To solve the issue, ensure that the Oracle client is installed and that the bit-level of the client matches the bit-level of the connecting application.

If both the 32-bit client and the 64-bit clients are installed on the same machine, the 64-bit client must be listed first in the PATH environmental variable for a Windows operating system.