One Flex error, one Flex Error

One Flex error, one Flex Error

1. Error description

TypeError: Error #1009: the attribute or method referenced by the null object cannot be accessed.
At com. gwtjs. components: DetailWindow/completeHandler () [D: \ Adobe Flash Builder 4 Installer \ demo \ src \ com \ gwtjs \ components \ DetailWindow. mxml: 25]
At com. gwtjs. components: DetailWindow/___ detailwindow_titlewindow?creationcomplete () [D: \ Adobe Flash Builder 4 Installer \ demo \ src \ com \ gwtjs \ components \ DetailWindow. mxml: 5]
At flash. events: EventDispatcher/dispatchEventFunction ()
At flash. events: EventDispatcher/dispatchEvent ()
At mx. core: UIComponent/dispatchEvent () [E: \ dev \ 4.0.0 \ frameworks \ projects \ framework \ src \ mx \ core \ UIComponent. as: 12266]
At mx. core: UIComponent/set initialized () [E: \ dev \ 4.0.0 \ frameworks \ projects \ framework \ src \ mx \ core \ UIComponent. as: 1577]
At mx. managers: LayoutManager/doPhasedInstantiation () [E: \ dev \ 4.0.0 \ frameworks \ projects \ framework \ src \ mx \ managers \ LayoutManager. as: 759]
At mx. managers: LayoutManager/doPhasedInstantiationCallback () [E: \ dev \ 4.0.0 \ frameworks \ projects \ framework \ src \ mx \ managers \ LayoutManager. as: 1072]

2. Error cause

3. Solution

FLEX Error

<? Xml version = "1.0" encoding = "UTF-8"?>

Flex error: Undefined access method

Var item_3: ContextMenuItem = new ContextMenuItem (".....");
Var a: ContextMenu = new ContextMenu ();
A. customItems. push (item_3 );
A. hideBuiltInItems (); I compile it here by changing the reference name.