Hi,
The right file is the 56834x_flash.cfg.
May be you have another problem regarding the connection to the board.
By default if the wrong cfg file is used you should get antoher message like downloading problem.
The CCS is a tool used to establish the connection with the board.
I think it should be better you contact the support team for that.
You can log the request via the web:
Pascal
Freescale - CodeWarrior Support