Specifies the username and password for accessing the database engine in basic user operations. If this property is NULL when creating or attaching a vault, M-Files Server creates a new account with a default username and a random password.Specifies the username and password for accessing the database engine in basic user operations. If this property is NULL when creating or attaching a vault, M-Files Server creates a new account with a default username and a random password. If this property is NULL when calling the UpdateVaultProperties method, the previously set username and password remain unchanged. Specify NULL for this property if the database engine is Firebird.