it is caused by using <visible>!Window.IsVisible(fullscreenvideo)</visible> in the dialogbusy dialog.
according to jmarshall, the problem is probably the following (quoted from our github issues page)
Quote:1) DVDPlayer takes a while to open, so it pops up the busy dialog.this is our work-around which fixes the problem.
2) It eventually opens, calling close on the busy dialog. This queues up the close anim on that dialog.
3) The screen switches to fullscreen immediately, before the next process loop runs (i.e. no updating of controls)
4) The next process loop runs.
5) The image control's UpdateVisibility runs, which hides the image and sets m_hasRendered to false.
6) The image animate() is called to update the animation status on this image, but it never begins, because m_hasRendered is false (we only allow it to start animating once it's been through the render cycle once).
7) As Render() is never got to (the control is invisible) it's always marked as animating.
8) Thus, the dialog never closes.
This will almost certainly crop up elsewhere. I'm pretty sure it can only happen if step 5 happens immediately after step 2. It might be reproducible by have an image control with a window close anim also having !Window.IsActive() in it's condition. (eg put an image in the context menu dialog, give it a close anim, and also give a visible condition with !Window.IsActive(ContextMenu))
(we want to hide the black bg overlays of some dialogs when a movie is playin)
ask if you need more info