Factorio Forums

If you create a GUI element, then later change its caption or tooltip, locale fallback groups are not parsed. They only work when setting the caption or tooltip on initial creation of the GUI element.

To reproduce:
Run this command: The first button will correctly show no ice cream, but the second button will show Unknown key: "?".

Adding: it also doesn't work in just game.print:

Based on this I recognize a pattern that is probably relevant: in LuaGuiElement.add the entire structure gets converted to a PropertyTree first, including the localised string. Assigning to LuaGuiElement.caption doesn't do that, neither does game.print, neither do most things (edit: that take localised strings), so these are most likely 2 different parse functions.

Thanks for the report. This and other issues with fallback group parsing are fixed for the next release.