Factorio Forums

I was learning and faced with such a problem. I tried to put the iron plate in the loader with ctrl + left click and saw a strange message. I think this is a flaw: Unknown key: "gui.not-operable"

I cannot reproduce this. I guess it was fixed, the locale just works for me. Maybe try updating your game.

Edit: Found the commit that fixed this, it's part of 0.17.3 :)