In all past episodes there was a Russian localization, 4 episodes downloaded, but did not want to run because writes that there is no Russian.
Сохраните сейвы игры перед удалением!!!!! Используйте команду выполнить (Сочетание клавиш Win+R) и пропишите туда %USERPROFILE%\Documents\Telltale Games - папка, где лежат сейвы
Решил проблему так - удалил Batman The Enemy Within в GOG Galaxy, удалил GOG Galaxy, скачал игру через GOG Downloader вместе с патчем. Установил. Всё работает, языки обновляются.
Warning!!!! Before deleting the game - copy your saves!!!!! Use Win + R combination and paste this %USERPROFILE%\Documents\Telltale Games - thats where your saves is.
Solution for me - Delete Batman The Enemy Within in GOG Galaxy, Delete GOG Galaxy (maybe you can skip this if you have many games in it - i dont know), Download Game via GOG Downloadre with Patch, Install game..... Profit. If your saves is dead - restore them frome the copy you made.
I had the same problem with French language, but this solution didn't work for me (I didn't delete GOG Galaxy, because I have other games in it).
But I found another one that did.
So, I went to %USERPROFILE%\Documents\Telltale Games and made a backup copy of the folder "Batman The Enemy Within - The Telltale Series", just in case.
In this folder, I deleted those file :
Then, I launched the game. It crashed a first time. After relaunching it, I could start episode 4. The game only asked me to re-calibrate brightness (move the cursor to almost see the bat logo).
So, that is the solution that worked for me. I think it means that at least 1 of the 3 files was corrupted with the update.
I hope it will help if you face the same kind of problem, whatever the language.