CallerMemberName | AmbiguousMatchExcpetion

I get the following error on runtime: AmbiguousMatchExcpetion "Ambiguous Match found."

Does someone knows what is the reason for?

Class

public class HtUserGroupSetup : HtUserGroup
{}    

Property

public HtUserGroupSetup CurrentUserGroupSetup
{
    get { return _CurrentUserGroupSetup; }
    set
    {
        if (_CurrentUserGroupSetup != value)
        {
            _CurrentUserGroupSetup = value;
            OnPropertyChanged();
        }
    }
}
private HtUserGroupSetup _CurrentUserGroupSetup;

Screenshot

StackTrace

bei System.RuntimeType.GetPropertyImpl(String name, BindingFlags bindingAttr, Binder binder, Type returnType, Type[] types, ParameterModifier[] modifiers)