New Post: TaskSchedulerWizard crashes w. NullReferenceException

I think you have run across a bug that I have fixed for the next release (1.9.3). I should be posting it in the next few days. Also, I thought I'd make you aware of the TaskFolder property on the wizard. Using it, your code would look like:

string FolderName = "My Folder";
using (var ts = new TaskService())
{
   var taskFolder = ts.RootFolder;
   if (ts.HighestSupportedVersion > new Version(1, 1))
   {
      try
      {
         taskFolder = ts.GetFolder(FolderName);
      }
      catch (System.IO.FileNotFoundException)
      {
         taskFolder = ts.RootFolder.CreateFolder(FolderName);
      }
   }

   using (var taskSchedulerWizard = new TaskSchedulerWizard())
   {
      var newTaskDefinition = ts.NewTask();
      newTaskDefinition.Actions.Add(new ExecAction("notepad.exe"));
      taskSchedulerWizard.Initialize(ts, newTaskDefinition);
      taskSchedulerWizard.TaskFolder = FolderName;
      taskSchedulerWizard.RegisterTaskOnFinish = true;
      taskSchedulerWizard.AvailablePages = TaskSchedulerWizard.AvailableWizardPages.IntroPage |
         TaskSchedulerWizard.AvailableWizardPages.SecurityPage |
         TaskSchedulerWizard.AvailableWizardPages.SummaryPage |
         TaskSchedulerWizard.AvailableWizardPages.TriggerPropertiesPage |
         TaskSchedulerWizard.AvailableWizardPages.TriggerSelectPage;

      if (taskSchedulerWizard.ShowDialog() != DialogResult.OK) return;
   }
}