Layout editor won't render (and shows a sad face)

Sometimes the layout editor in C3 stops rendering the layout and instead just shows a sad face in the upper left corner (pic below). When this happens, none of the 10+ layouts in my game will render properly. The only solution I've found is to close the project, restart the browser (chrome), and reload the project. Any idea why this may be happening, and is there anything I can check to track down the underlying cause?

I've had this happen when the chrome viewing scale has been changed.

It means your graphics driver crashed. It's particularly common on older hardware. Try installing any available system software updates or driver updates for your graphics card if any are available.