Hi Raymond,

Have you resolved the issue? Seems that I have faced the same..

Works in EPiServer 9 at least...tried this:

  [ModuleDependency(typeof(EPiServer.Web.InitializationModule))]
    public class EventsInitialization : IInitializableModule
    {
        private IContentEvents _contentEvents;
        public void Initialize(InitializationEngine context)
        {
            if (_contentEvents == null)
            {
                _contentEvents = ServiceLocator.Current.GetInstance<IContentEvents>();
            }
            _contentEvents.MovingContent += Moving;

....

 private void Moving(object sender, ContentEventArgs e)
        {
            var args = e as MoveContentEventArgs;
            if (args != null)
            {
                args.CancelAction = true;
                args.CancelReason = "this didn't work out at all";
            }
        
            
        }

....

  public void Uninitialize(InitializationEngine context)
        {
            if (_contentEvents == null)
            {
                _contentEvents = ServiceLocator.Current.GetInstance<IContentEvents>();
            }
            _contentEvents.MovingContent -= Moving;

...

Works like a charm!