Method 1:
- Login to your control panel.
- Enter your configuration editor, click text editor next to serverconfig.txt
- Find the 'difficulty' line and change the value to 2
- Save and apply.
- Restart your server.
Method 2:
- Login to your control panel.
- Enter your configuration editor, click configuration editor next to serverconfig.txt
- Ensure the auto create check box is checked
- Change the difficulty dropdown to Master
- Save and apply.
- Restart your server.
Note: You will need to generate a new world for this to work, for help on how to generate one click here.
Work Around (before they patched it):
- Login to your control panel.
- Click onto the actions tab and click Download Master World
- Enter your configuration editor by clicking configuration editor next to serverconfig.txt
- Ensure the auto create checkbox is not checked
- Set the world name to MasterWorld
- Save and apply.
- Restart your server.