The extensions have been updated to work with CC 2015. You will have to download and install the latest versions for it to work.
see this post if you still have issues: http://www.webassist.com/forums/posts.php?id=37620
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.