MikeMaximus: I finally figured out what else can cause this missing text problem.
The game stores it's fonts and localization information in "C:\Users\*User*\Documents\This War of Mine", instead of the game installation folder, where it would actually make sense.
On my machine with the missing text problem, both C:\Users\*User*\Documents\This War of Mine\LocalizationPacks and C:\Users\*User*\Documents\This War of Mine\LocalizationBinFonts were empty for some reason. And on my machine that was working they were filled with various fonts and data.
I deleted that folder from Documents and re-installed the game with Galaxy, which fixed it finally by re-installing the missing fonts and information to the Documents folder.
So basically if something happens to that folder in Documents, all in-game text will disappear. This is likely the reason why some people have to run the game as administrator, so they have proper access to the Documents folder where the fonts and localization data got installed.
I'm not sure why the devs are storing required game data in that location, it's horribly bad practice.
OMG, that finally fixes this damn issue which I've been hunting for >1 year now, even reported it to devs official support email (never received a reply btw). THANK YOU SO MUCH!
Yes, on my system I install applications as a different user (an admin user) than the user I use to run them as (a non-priviledged user) so installing TWoM installed those font files in the administrator user directory (instead of game directory) and then tried to read them from my regular user directory when running so it could not and thus displayed no fonts.
I added this solution to the relevant pcgamingwiki section and used your post as reference link, THANKS AGAIN!