New Post: VS 2015 and AvalonDock troubles

Hi all

I'm using W8.1 and VS2015CE.
Sorry for maybe the noob question, but happens the following in a wpf project i have included AvalonDock (last version downloaded from here).
The correspondent dll is in references and i also have the controls on toolbox...
The xlns is correct i think: xmlns:av="http://schemas.xceed.com/wpf/xaml/avalondock"
I also unlocked the dll's but i continue to get the error "The name "DockingManager" does not exist in the namespace...". I do not have autocompletion, but i can build the project...
The problem is i can't see the design of wpf.
Any ideia to a solution to this problem ?
TIA

Regards
JL