The files might be present on your hard drive, but the Windows Registry or game configuration files are pointing to the wrong language code.
In the main game folder, look for a file named steam_api.ini , context.txt , or a similar configuration file. Open it using Notepad. Use Ctrl + F to search for the line: Language= Change the value to: Language=english Save and close the file. Troubleshooting Common Issues Game Crashes on Launch
Steam’s integrity verification overwrites modded files. Solution: Disable automatic updates for Prototype 2 . Go to Steam → Library → Right-click Prototype 2 → Properties → Updates → "Only update this game when I launch it". Then, always launch the game directly from the .exe file, not through Steam.