When connecting to E-Notebook, Users were getting the following error:

• When connecting to E-Notebook, Users were getting the following error:

  -------------------------------------------------------------------------------------------
  Unknown error opening database connection: ORA-12638: Credential retrieval failed.
  -----
  OK
  -----

  Applicable Version:
  E-Notebook 13.9.x

Cause:

This was due to trust relationship issue with the Application server.

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:

Solution:

Note: - This should be done by IT Team.

• Re-adding the server to the domain should fix the problem (or)
• Locate the sqlnet.ora file on the client system which is by default in directory:

1. $ORACLE_HOME/network/admin
2. Locate the following entry: SQLNET.AUTHENTICATION_SERVICES=(NTS)
3. Replace the original entry with the following: SQLNET.AUTHENTICATION_SERVICES=(NONE)

FYI: When set to NTS, Oracle tries to authenicate User using User’s windows credentials.

(Or)

• In windows, bounce the server (stop and re-start) the window services for oracle.