Hi, For the sake of helping a fellow learner (who stumbled on my topic via searching on the forums), here's what I have found: - Calling nativeWindow.close() with "HTMLLoader.createRootWindow(TRUE ..." never gave me any problems (so far :) - Calling nativeWindow.close() on a hidden window which was brought back visible manually using activate() was the culprit, depending on how it has been activate()'d In my testcase (below), using the activate() under the anonymous function defined in winbox_loadcomplete will throw the TypeError error mentioned in my other post. By commenting this activate() line and uncommenting showwindow() inside the string, everything will work fine, error-free. My guesses: either i am using the wrong object for remotely closing my window (HTMLLoader.window.nativeWindow.activate() ), or something obscure (I should read up more though) about the AIR security prevents me to do it remotely. Any guesses / ideas / pointers? Trimmed down source code: nativeWindow.close() TypeError test case

Isolated sample:
nativeWindow.close() throwing a TypeError

Note: The bug occurs when we're using the follwing path: HTMLLoader.window.nativeWindow.activate(),
calling from the parent (initial) window.

By calling window.nativeWindow.activate() directly from the child window, the bug does not occur.