V2 Admin area not correct working due to layout failure

I have done an upgrade and a new install of version 2.0. The public store is working fine but the admin area is not correct. The menu items are shown as a tree view.

I have updated all the server files, but running out of idea's on what the problem could be.

Anybody has an idea on how to solve this

Can you make a screenshot?

I have or had a similar problem, I believe.  See this post:

https://www.nopcommerce.com/boards/t/11112/trouble-displaying-admin-area.aspx

After a lot of googling I solved it to at least some extent by putting this in the web.config file.

 
   <system.webServer>
   <staticContent>
            <clientCache cacheControlMode="UseMaxAge" cacheControlMaxAge="30.00:00:00" />
        </staticContent>
        <urlCompression doDynamicCompression="true" />
    </system.webServer>

It seems to take a little while for it to 'engage', but it seems to solve my problem.  I have no clue if it is a good or bad idea with NopCommerce in general.

I'm also not sure about it. The menu was developer by Telerik. It's part of their MVC Extensions. Perhaps, it would be better to ask an advise on their forums