gui = create_gui()

gui:attach_button{
	label="Press Me",
	x=0,y=0,w=64,h=64,
	click=function(self)self.hidden=true end
}

function _update()
	gui:update_all()
end

function _draw()
	gui:draw_all()
end

Hiding a button throws an error at line 959 due to el being null. The if statement checks for dragging_el but does not check for el, which has become null due to become hidden on line 833.

I propose a check for el check on line 953 so an error is not thrown.

I understand that tap can be used instead and this avoids the issue, but wanted to mention as seems common enough implementation.