internal void OnSolutionLoaded(Solution solution)
 {
     try {
         if (solution.HasDnxProjects ()) {
             LoadDnxProjectSystem (solution);
         }
     } catch (Exception ex) {
         LoggingService.LogError ("DNX project system initialize failed.", ex);
         UnloadProjectSystem ();
         initializeError = "Unable to initialize DNX project system. " + ex.Message;
         OnProjectSystemFailed ();
     }
 }