(Hopefully) fixed the bug that gave an error when trying to change the gamemode.
It works fine for me, if it's not working for you, try updating Skript! This script is NOT compatible with 1.7.
Also, I've reverted the dependency back to Umbaska. If you're having any errors, make sure you're using the 1.10 Umbaska found here.
I would also recommend using a 1.9 version of Skript, even if you're on 1.10 (it should still work).