Steps to reproduce:

1. Go to the skin chooser.
2. Choose any skin from the Mario Mash-Up pack (such as regular Mario)
3. Go to Play and create or edit a world.
4. If the skin is set correctly, you should see a warning about your "Platform Restricted Skin". Choose Continue.
5. Go to the Multiplayer settings menu.

What I expected to happen was:
I would be able to toggle the Multiplayer Game option.

What actually happened was:
The option to toggle Multiplayer Game is disable, requiring me to go back and change my skin to something outside of the Mario Mash-Up pack before I can toggle Multiplayer Game.