ORA-12638: credential retrieval failed tips

Oracle Error Tips by Stephanie F.

Question: I am getting the ORA-12638 error when I try to connect to Oracle:

SQL> connect sys as sysdba;

ORA-12638 credential retrieval failed

How do I resolve this ORA-12638 error?

Answer: The Oracle docs note this on the ora-12638 error:

ORA-12638: Credential retrieval failed

Cause: The authentication service failed to retrieve the credentials of a user.

Action: Enable tracing to determine the exact error.



The original question was referring to a problem installing Oracle Designer, in which the user was thrown ORA-12638 when testing the connection, before the installation had completed.

The ORA-12638 is an Oracle database error, indicating that the SQL*Net client was unable to connect to the database. In Windows, the Oracle Windows client attempt to use your current Windows domain credentials to authenticate you with the Oracle server. This could fail because the Windows box is not configured to support Windows authentication or because the credentials you use to login to your local machine are not sufficient to allow you to login to the server. There are several possible resolutions for the ORA-12638 error:

1: In on Windows, bounce the server (stop and re-start) the Windows services for Oracle.

2: The following direction was given, and once administered, was a successful resolution to ORA-12638:

Please change the sqlnet.ora file in the $ORACLE_HOME/network/admin directory. Change the following entry and the ORA-12638 error will disappear:

Change - SQLNET.AUTHENTICATION_SERVICES= (NTS)

To: - SQLNET.AUTHENTICATION_SERVICES= (NONE)

refference : http://www.dba-oracle.com/t_ora_12638_credential_retrieval_failed.htm