You should always test your upload on the site to make sure it is doing what it should there. As soon as you click 'Run', the 'Pause' button flashes and the scenario stops and the 'Run' button reappears. There is an error being thrown that is preventing the scenario from running.

@Super_Hippo, the scenario is called 'Hexagonal SuperWorld. You can find it at the following address: http://www.greenfoot.org/scenarios/10574

@Upupzealot, I believe you are technically correct. You could, however, consider what happens in one act loop as a frame, in general terms.