Bookmarks Manager from Browser Example

I have copied bookmarks widget code from browser example to my app.
Bookmarks toolbar and bookmarks window are working but bookmarks menu not.
I have created and added bookmarks menu to my menu, but after compiling if i try to open menu with bookmarks, my app shuts down. But if i comment

Code:

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connect(this, SIGNAL(aboutToShow()), this, SLOT(aboutToShow()));

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app will not shuts down but bookmarks are not imported to menu. What i do wrong??