Grid window does not show?

1

Grid/Simulation window does not show for one of my students. I can see the code window on his screen, and he can drag codeblocks out to the area, but when he clicks on “Launch” from pull-down menu, nothing happens. The code window takes up the whole screen, and the green toolbar is not visible either. He is logged in and can save missions, but cannot view the drone executing the code. Any suggestions? He is not on an Apple device, or handheld.