closing a node in a stackpanel

Question

I have this project where I have a stackpanel with control elements, each control element has a property called MyNextNode which contains the next object in the chain. My problem occurs when I try to close one of the nodes in this chain. I get the error "Value does not fall within the expected range." here is my code. WFElement orignextnode = this.NextNode this.PrevNode.NextNode = orignexnode Next node is a dependency property that triggers this code when changed protected static void OnNextNodeValueChanged(DependencyObject o, DependencyPropertyChangedEventArgs e) { WFElement wfe = o as WFElement; WFElement newElem = null; if (e.NewValue != null) { newElem = e.NewValue as WFElement; wfe.MyNextNode.Content = newElem; } else { wfe.MyNextNode.Content = null; } if (e.OldValue != null && newElem != null) { newElem.NextNode = e.OldValue as WFElement; } } I get that error on {wfe.MyNextNode.Content = newElem;}. If I change the second line to this.PrevNode.NextNode = null; it works however, if there are elements after the deleted element, they get deleted as well. Thank you in advance