When you first open a page in dreamweaver after the update, the webassist installer should run. Did that happen?
Then it asks you to restart Dreamweaver when it completes. Did you get this message?
YES! Yet same errors after restart
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.