title: "Cannot resolve symbol 'system'" and other namespaces when using ASP.NET 5 in VS2015 Community
body: <p>In VS2015 Community, when I create an ASP.NET 5 project, I get many errors with namespaces and I'm not sure why that is.</p>
  
  <p>I have downloaded VS2015 Community and have downloaded Microsoft ASP.NET and Web Tools 2015 (Beta8) and followed the install instructions on the Web Tools Beta8 page and installed .NET Version Manager (Beta8) prior to the Web Tools. In VS2015, I click on New Project, go to Web within the Visual C# section and select "ASP.NET Web Application". Then I select the "Web Application" template within ASP.NET 5 Preview Templates. It creates my project. I can start debugging by click on the green play button with "IIS Express" text and the page loads in my web browser as it should. However, almost all of the namespaces are flagged as '"Cannot resolve symbol". I have tried uninstalling and reinstalling and that has not worked. In the Solution explorer, I have two references, DNX 4.5.1 and DNX Core 5.0 and these have a fair number of references within those. I noticed that only DNX 4.5.1 has "Framework Assemblies" containing Microsoft.CSharp, mscorlib, System and System.Core.</p>
  
  <p>The same issue occurs when I select the "Empty" ASP.NET 5 Preview Template</p>
  
  <p>Images:
  <a href="http://i.stack.imgur.com/fRw5G.png" rel="nofollow">What my Startup.cs looks like in VS2015</a>, <a href="http://i.stack.imgur.com/Rmwem.png" rel="nofollow">References in Solution Explorer</a></p>