After I installed the upgrade and lauched DW CC 2015 for the first time, the WA extensions seemed to install themselves - I got the 1, 2, 3, .... install dialog box and at some point it said it was finished and the installation completed. Yes, I do have the Webassist menu option across the top. I just get this ugly error message when I try to run anything. I'm sorry, it was yesterday and I didn't write it down.
Just so I can finish my current project, which shouldn't take more than a week, I need to fall back on an older version of DW. Then I'll get back to this thorny issue. Some of my problems are that the new version of DW has deprecated many of the features I used daily (server behaviors, bindings tab, database connection tabs, etc.) so I have to learn where everything is and what the new procedures are. Then I'll be back in touch.