title: File system enumerator throwing error
body: <p>I am calling the following code on a mapped folder to another share</p>
  
  <pre><code>private static void CheckFileNaming(string path)
  {
      var di = new DirectoryInfo(path);
      foreach (var fi in di.EnumerateFiles())
      {
          if (fi.Name.EndsWith(".battxt"))
          {
              var name = fi.FullName.Substring(0, fi.FullName.Length - 3);
              TaskLogger("Rename " + fi.FullName + " to " + name);
              File.Move(fi.FullName, name);
          }
      }
  }
  </code></pre>
  
  <p>However I am getting the error</p>
  
  <pre><code>2016-04-26 11:00:58Z: Error occurred:    
     at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
     at System.IO.FileSystemEnumerableIterator`1.CommonInit()
     at System.IO.FileSystemEnumerableIterator`1..ctor(String path, String originalUserPath, String searchPattern, SearchOption searchOption, SearchResultHandler`1 resultHandler, Boolean checkHost)
     at System.IO.DirectoryInfo.EnumerateFiles()
     at Centrica.EMT.SE.CloudMaster.Program.CheckFileNaming(String path)
     at Centrica.EMT.SE.CloudMaster.Program.RunCombiner(String modelVersion, String pythonVersion)
  2016-04-26 11:00:58Z: Invalid Signature.
  </code></pre>
  
  <p>Which seems to imply there is a problem with simply enumerating the files but I have never seen this error before and cannot find anything on google. Has anyone seen this before?</p>