An exception occurs when trying to prevent users from double clicking to create a new appointment in the XAF Scheduler Control

Hello,
I'm trying to prevent my users from double clicking to create a new appointment in the XAF Scheduler Control. I have created a view controller that looks like the following:
protected override void OnActivated()
        {
            SchedulerControl control = SchedulerHelper.GetScheduler(this.View);
            if (control != null)
            {
                control.OptionsCustomization.AllowAppointmentCreate = UsedAppointmentType.Custom;
                control.AllowAppointmentCreate += new AppointmentOperationEventHandler(control_AllowAppointmentCreate);
            }
            base.OnActivated();
        }
void control_AllowAppointmentCreate(object sender, AppointmentOperationEventArgs e)
        {
            e.Allow = !this.View.ObjectType.IsAbstract;
        }
This works just dandy. But now when I right click on the scheduler I get a null reference exception. How do I prevent my user from creating appointments via double click and still allow the right click functionality? The right click popup menu functions normally if I set the UsedAppointmentType to NonRecurring or All but nothing else.
Below is my error log:
The error occured:
     Type: NullReferenceException
     Message: Object reference not set to an instance of an object.
     Data: 0 entries
     Stack trace:
   at DevExpress.ExpressApp.Scheduler.Win.SchedulerListViewController.scheduler_PreparePopupMenu(Object sender, PreparePopupMenuEventArgs e)
   at DevExpress.XtraScheduler.PreparePopupMenuEventHandler.Invoke(Object sender, PreparePopupMenuEventArgs e)
   at DevExpress.XtraScheduler.SchedulerControl.RaisePreparePopupMenu(PreparePopupMenuEventArgs args)
   at DevExpress.XtraScheduler.SchedulerControl.CreatePopupMenu(Point point)
   at DevExpress.XtraScheduler.SchedulerControl.OnPopupMenu(Point point)
   at DevExpress.XtraScheduler.SchedulerControl.OnWmContextMenu(Message& m)
   at DevExpress.XtraScheduler.SchedulerControl.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
     InnerException is null