I can't interact anymore with buttons in world creation menu...

Steps to reproduce:

1. go to world creation menu

2. you can enable or disable any feature if you want

3. click create world

Expected result:

the world should be starting to create as soon as you click the "create world" button. 

What happens:

as soon as you press "create world" button, you can't interact with any button at all. but if you wait long enough, it will pop up the loading world screen (the on with the xp bar in it) and then you can play on the world.