Diagnosis
There is no free line between the last element that would have beenenclosed by the box and the bottom edge of the screen. Consequently,the system cannot draw the bottom edge of the box.

System Response
The screen element could not be converted into a box.

Procedure
Enlarge the screen by at leats one line or move the screen element andall of the elements that you want to appear in the box, so that thereis at least one free line left at the bottom of the screen.