Hi, Installed was Thunderbird 60.3.1 but I had to delete this and re-install version 52.5 because an extremely important function does not work in the new version: I MUST be able to switch between GUI languages. The problem: general.useragent.locale is ignored. I like the new version, but for now I can't use it. Is there a way to get around this? Installing other versions or other profiles is unacceptable. I mus be able to switch quickly betweeb gui languages.