Version 2.0 of the game is required. Start the game with the /edit command line parameter. Go to a single player game and press CTRL + E. You will automatically go into the editor. Go to multi-player mode and start a session. Join a map, then once in the level, exit it. After that, click on "Chat/More". Note: This option will not be there unless you are playing v2.0 or later. You will be in the server again. Join a map again, and once in the level, press CTRL + E. The license agreement will appear. You can now continue editing.