Use the buttons on the Console page:
- Start boots the server.
- Restart stops the server cleanly, then starts it again. Use this after changing settings.
- Stop sends the game's proper shutdown command so the world is saved. Wait for it to finish.
- Kill appears if a stop hangs. It ends the process immediately, and anything not yet saved is lost. Use it only as a last resort.
Most setting changes on the Startup page only take effect after a restart.