Background graphics or elements may exceed the limits of the user's screen. This may happen, for instance, if a border-mode is used, as this is the intended behaviour.
Elements that display text might also be the cause of this, especially if the element's width is limited.
For these cases, vertical- or horizontal scrolling might be enabled by clicking the corresponding checkboxes.
Note: The screen always originates that the start of the canvas. It is never possible to go left from or above of the canvas.