KevinTheJedi FYI: LiteSpeed server, tried PHP 7.0, 7.1 and 7.3
I put the language module into /include/i18n.
The admin panel can find the language, and I set up the language as Primary Language as syetem language under setting. I didn't set up any Secondary langauge, så user's pages don't have any flag. So I assume that osTicket should show the Primary LANGUAGE, which is set up within setting.
Is there any incompatibility with LiteSpeed server? Does PHP need some special feature, which must be turned on?