Question: Error, (in Maplets:-Display) BoxCell contains an element (_Maplets_reference_1235) that cannot be placed in a layout.

I got my maplet and there error occurs when I try to display it - Error, (in Maplets:-Display) BoxCell contains an element (_Maplets_reference_1235) that cannot be placed in a layout.
Please correct Maplet definition.

How to fix it?

with(Maplets[Elements]);

mpt := Maplet(Window("Точка выше или ниже прямой", [[[ToggleButton[TB1]("Tt", 'group' = 'tb1')], [ToggleButton[TB2]("Tt", 'group' = 'tb1')]], ButtonGroup['tb1']()]));

Display(mpt);

Please Wait...