Hello! I need to create a little game with Greenfoot 3 as a school project. I decided to make a top down (space) shooter. But I really have big problems with coding all the stuff. There are 2 mayor issues I have. The first one: I want to remove an enemy after 3 hits. So I made an if statement and after 3 hits this.getWorld().removeObject(this). So far so good. But I also want to remove the Enemy if he reaches the edge of the screen (at the bottom). So I also made an if statement for that. The problem is the enemys get removed when they reach the border but as soon as I destroy an enemy the game crashes. I can't post code at the moment because we don't use the "real java". We made a stride project and we use the simple version where you can drag and drop code and don't need {}; (I don't know the name I hope you get what I mean). If I find out how to copy the code like real java code I let you know! Maybe you have some solutions in mind!