While enabling Oracle database VAULT with the tool dbca, and after creating a dedicated Oracle database user to be the Owner of the feature Oracle database Vault named “dbv_owner” as example, we find the FATAL error: “[FATAL] [DBT-09352] Error in validating dbv_owner credentials.”

Solution N°1: Case sensitive username, so may we create the dedicated user with quota
Solution N°2: We create the user without the permission “create session” or the role “connect“:
In our case is the solution N°2.
Enjoy!