So my problem is short, I have the French language set for the entire game but the DLC that I bought (southeastern, and TGV) are set in English for some reason the other game base train which is DB, London tube stock and CSX are in french, so if you have an answer write it below, thank you.
j'ai finallement réglé ce problème avec un discussion sur steam je vous la donne au cas ou i finally found an awnser on steam community, i give it here just in case : it's NOT a official solution temporary solution is: move all your DLC *.pak files from "Train Sim World 2\WindowsNoEditor\TS2Prototype\Content\DLC" to "Train Sim World 2\WindowsNoEditor\TS2Prototype\Content\Paks" *** this fix Chinese and this way should fix any other languages *** you should DISABLE auto update, so when Dovetail release update you can put them(*.pak) back