If you have removed all mods, repaired the game, and still see $STRING_ERROR in the base game menus (like the "Work" tab or Aspirations), this is an EA bug. In the meantime, switching your game language to German or Spanish and then back to English often forces a hotfix download.
A mod created before a recent game patch is referencing a text file that no longer exists or has been changed. sims 4 language strings fix
Wait for the process to verify all files. The app will automatically download any missing language strings. 2. Registry Fix (Windows Only) If you have removed all mods, repaired the