How to Resolve Arguments are not valid for System.

Question

I'm rewriting an ASP.NET MVC3 app in MVC5 which makes heavy use of Knockout and MVVM. The model classes are heavily laden with INotifyPropertyChanged and INotifyPropertyChanging functions.

While bringing the following statements into the MVC5 app, I'm receiving the build error in the subject line above:

public event PropertyChangingEventHandler PropertyChanging;
    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void SendPropertyChanging()
    {
        if (this.PropertyChanging == null)
            return;
        this.PropertyChanging((object)this, AFCity.emptyChangingEventArgs);
    }

What must be done to resolve the above error?