When moving around built-in 4D dialogs such as the Explorer, Tool Box, Structure Editor, etc., 4D will save the last coordinates of the window before it is closed. Therefore, the next time the window is opened, it will open at those coordinates. While useful for when the developer wants to have to have organized placement of all their 4D windows, it may prove to be a problem if one of the windows didn’t open where it was supposed to, and the developer can’t find it.

In that event, just hold down the SHIFT key before clicking on the toolbar buttons to open the 4D window, and the window will open in the center of the screen.