Tag Archives: ORA-12638

Simple solution for ORA-12638: Credential retrieval failed

If the Oracle client was installed using the domain administrator account instead of the local administrator, the following message could be displayed when trying to connect:

ORA-12638: Credential retrieval failed

From the wording of the error message one could think that this error means that he is using the wrong password but this is not the case. To solve this:

1) Go to /oracle home/network/admin and open sqlnet.ora

2) Search for  SQLNET.AUTHENTICATION_SERVICES= (NTS) and change it to

3) Save the file and try to connect, this should work