This is because our extensions haven't been updated to work with Dreamweaver CC 2015. We are working on this issue and will be putting out an update soon.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.