You shouldn't be opening the mission editor. Here is how you start it.1. Find blockland.exe.2. Right click it and select "Create shortcut"3. Right click the shortcut, and select properties.4. Go to the field that says target. Click inside of it, press the end key, and type -mod editorIt should now look like this:"C:\Program Files\Blockland\blockland.exe" -mod editor5. Click okay.6. Start the game using the shortcut.7. Open a mission.8. Press F11.