To reproduce:
Run this command:
Code: Select all
/c game.player.gui.top.add{type = "button", caption = {"?", {"item-name.ice-cream"}, "no ice cream"}} game.player.gui.top.add{type = "button", name = "test"} game.player.gui.top.test.caption = {"?", {"item-name.ice-cream"}, "no ice cream"}