ORA-12638: "Credential retrieval failed" message when browsing the Oracle APM (78903)

Date - Sep 2008
Affected Product & Version - NVBU 8.1
Affected Module & Version - APM for Oracle (Version 5.5)
OS Version - Windows only
Application Information - Oracle 10.0.2.x


Symptoms:

"ORA-12638: Credential retrieval failed" Error generated when trying to browse an Oracle Database through the APM

Check the Oracle sqlnet.ora file, if you have an entry that reads:
SQLNET.AUTHENTICATION_SERVICES= (NTS)
Then edit this to read:
SQLNET.AUTHENTICATION_SERVICES= (NONE)
And restart the Listener.


Explanation:

This error is generated by Oracle and means that the specified authentication service cannot authenticate the user details. This is most common on a Windows server where Active Directory is not returning expected values.

Note that setting the Authentication service to NONE means that a SQL login and password will always be required, so this may have further ramifications on the Oracle server.

Alternatively, Oracle recommend enabling SQLnet trace to see what error is actually being generated by the authentication service.