I think you don’t need to modify defaultGame.ini to put the settings unless you have this -LocalizationPaths lines included.
If you go into Project Settings in Unreal Engine, then into Packaging you have “Localizations to Package”, click on “show Localized” and when you will be scrolling the list (English is listed also per dialects so a long list) you will find the other languages you have localized but are not included in the build, but they are causing errors since you is calling them or trying to call