title: System.Environment definition are missing in WIndows 8.1 app
body: <p>I am making a windows 8.1 store app. I want to set a default directory to cashe some images and am using this code to do it:</p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.IO;
  using System.Linq;
  using System.Text;
  using System.Threading.Tasks;
  
  namespace YouMaps.Tiles
  {
  class TileLoader
  {
      public const string defaultCasheName = "YouMapsTileCashe";
      public static string defaultCasheDirectory = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData), "YouMaps");
  </code></pre>
  
  <p>I am getting an error that System.Environment does not contain definitions for GetFolderPath and SpecialFolder. I F12'ed over Environment and sure enough, this was all that was in there </p>
  
  <pre><code>#region Assembly System.Runtime.Extensions.dll, v4.0.0.0
  // C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETCore\v4.5.1\System.Runtime.Extensions.dll
  #endregion
  using System.Security;
  
  namespace System
  {
  public static class Environment
   {
  
      public static int CurrentManagedThreadId { get; }
      public static bool HasShutdownStarted { get; }
      public static string NewLine { get; }
      public static int ProcessorCount { get; }
      public static int TickCount { get; }
      public static void FailFast(string message);        
      public static void FailFast(string message, Exception exception);
   }
  }
  </code></pre>
  
  <p>However, when I look on with windows MSDN it seems to show that even windows 8.1 should have access to the full range of definitions. I have searched using Google and just inside of stack overflow to see if anyone else has had this problem but I have found nothing even remotely like it. So, the question-Can anyone tell me why my Environment is "missing" the 90% of its definitions and secondly, how do I fix it? </p>
  
  <p>oh, and here are my references:</p>
  
  <pre><code>.NET for Windows Store apps
  Bing Maps for C#, C++, or Visual Basic
  Microsoft Visual C++ 2013 Runtime Package for Windows
  SharpKml
  Windows
  </code></pre>
  
  <p>Thanks for reading my question and providing help. This is the first question I have ever asked so if I broke some rules etiquette or failed to include some pertinent information let me know.</p>