# DDS

1. Error message: Command failed with error 18 (AuthenticationFailed): 'Authentication failed.' on server xxx.xxx.xx.xx:xxxx. The full response is { 'ok' : 0.0, 'errmsg' : "Authentication failed.", "code" : 18, "codeName" : "AuthenticationFailed" }
   1. Error cause: The username or password of the DDS DB instance is incorrect.
      Solution: Check whether the username or password is correct. If you are not sure, view the username or reset the password on the DDS console.
      Changing the password may affect services.
   2. Error cause: The entered username does not have the permission to access the database.

      Solution: Check whether the username has the permission to access the database. If you are not sure, connect to the admin database as user rwuser. Then check whether the entered username has the required permission.

Parent topic: Connection Management (Development Tool)