There is a strange bug at the moment where I have “sudden lights out” when all goes black on the game screen and all I can see are the avi names.
Thanks to zuz, we have figured out, if you drag the border of the game bigger or smaller, the game resets itself, turns the lights back on and you can see again.
There is no pattern to the lights out but if you do suffer with it too occasionally, just drag your game screen bigger of smaller.