How to fix the Oracle error TNS-12661: Protocol authentication to be used?

In this post, you’ll learn more about the Oracle ErrorTNS-12661: Protocol authentication to be used with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

TNS-12661: Protocol authentication to be used

Reason for the Error TNS-12661: Protocol authentication to be used

Cause: The Oracle Advanced Security authentication service has determined that the Oracle Net transport protocol in use is to be utilized to authenticate a user’s identity.

How to fix the Error TNS-12661: Protocol authentication to be used ?

You can fix this error in Oracle by following the below steps

Action: This error is used solely to communicate information between the authentication service and the Oracle Net session layer and should not normally be visible. If the error is seen, contact Oracle Worldwide Support.