ORA-62731
Required credential is not specified for a cluster associated with an Oracle Streaming Service 'stream'.
Cause
The specified credential name was NULL for a cluster whose provider is the Oracle Streaming Service (OSS).
Action
The password required for Oracle Streaming Service must be stored as a database credential using the SYS.DBMS_CREDENTIAL.CREATE_CREDENTIAL() procedure or an equivalent procedure. Specify the database credential name that was registered for the cluster associated with Oracle Streaming Service.