title: Exception at REngine.SetEnvironmentVariables() call
body: <p>I am getting an exception at REngine.SetEnvironmentVariables() in my below code, may I know how can I check the environment variables are set correctly.</p>
  
  <pre><code>static void Main(string[] args)
      {
          REngine.SetEnvironmentVariables(); // &lt;-- May be omitted; the next line would call it.
  
          REngine engine = REngine.GetInstance();
          // A somewhat contrived but customary Hello World:
          CharacterVector charVec = engine.CreateCharacterVector(new[] { "Hello, R world!, .NET speaking" });
          engine.SetSymbol("greetings", charVec);
          engine.Evaluate("str(greetings)"); // print out in the console
          string[] a = engine.Evaluate("'Hi there .NET, from the R engine'").AsCharacter().ToArray();
          Console.WriteLine("R answered: '{0}'", a[0]);
          Console.WriteLine("Press any key to exit the program");
          Console.ReadKey();
          engine.Dispose();
      }
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/eLbWW.png" rel="nofollow noreferrer">Visual studio Exception</a></p>