"Webassist 2.1.3" Do you mean SiteAssist 2.1.3?
Site Assist 2 is not compatible with DWCS5, you will not be abel to use site Assist 2 in this version of Dreamweaver.
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.