title: Error in Visual Studio Code Dotnet Core C#: "The type or namespace name 'System' could not be found", but build succeeds
body: <p>When trying to work with Visual Studio Code on a C# DotNet Core MVC application, I am having a lot of trouble getting visual studio code to work. It is having trouble finding anything related to C#, marking even 'Using System;' as invalid, saying it can't find it. </p>
  
  <p>However, when I run a Dotnet build, it succeeds with no warnings or errors and the project runs.  </p>
  
  <p>My project.json:</p>
  
  <pre><code> {
    "version": "1.0.0-*",
    "buildOptions": {
      "debugType": "portable",
      "emitEntryPoint": true
    },
    "dependencies": {
      "Microsoft.NETCore.App": {
        "version": "1.1.0",
        "type": "platform"
      },
      "Microsoft.EntityFrameworkCore.Sqlite": "1.1.0",
      "Microsoft.EntityFrameworkCore.Design": {
        "version": "1.1.0",
        "type": "build"
      },
      "Microsoft.AspNetCore.Mvc": "1.1.0",
      "Microsoft.AspNetCore.Server.IISIntegration": "1.1.0",
      "Microsoft.AspNetCore.Server.Kestrel": "1.1.0",
      "Microsoft.Extensions.Configuration.EnvironmentVariables": "1.1.0",
      "Microsoft.Extensions.Configuration.FileExtensions": "1.1.0",
      "Microsoft.Extensions.Configuration.Json": "1.1.0",
      "Microsoft.Extensions.Logging": "1.1.0",
      "Microsoft.Extensions.Logging.Console": "1.1.0",
      "Microsoft.Extensions.Logging.Debug": "1.1.0",
      "Microsoft.Extensions.Options.ConfigurationExtensions": "1.1.0",
      "Microsoft.AspNetCore.StaticFiles": "1.1.0"
    },
  
    "frameworks": {
      "netcoreapp1.1": {
        "dependencies": {
          "Microsoft.NETCore.App": {
            "type": "platform",
            "version": "1.1.0"
          }
        },
        "imports": "dnxcore50"
      }
    }
  }
  </code></pre>
  
  <p>Any ideas? I'm really pulling my hair out with this one. </p>