Make sure that you have installed the latest update the CC extension manager.
In the extension manager, it should show the version of Dreamweaver being managed as Dreamweaver CC 2014.
make sure to also install the Server Behaviors extension:
Then in the extension manger, install the WebAssist Extensions, open DW to start the WebAssist installer. If the WebAssist installer does not launch automatically, open a php page to start it.
make sure to restart DW after the WebAssist installer completes.
if you continue to have problems, please provide more details, saying "it does not work" is not really helpful, please describe the what it is you are trying to do, how you are trying to do it, and the outcome versus the expected outcome