My friend started playing recently and wanted to set up his hotkeys the same as mine. He was able to set it up completely the same except the 4th hotbar, in which ctrl+shift+1-6 worked, but not any of the letter keys. I normally bind Q, E, F, G, Z, and V for the last six slots of each hotbar. None of them were working.

Anyone got any ideas why it wouldn't let him?