Rockstar updates keys even in minor patches. Version 1.0.3028.0 (The Contract update) uses a different key than 1.0.3179.0 (Los Santos Drug Wars). Check your GTA5.exe properties > Details > Product Version. Match the key exactly.
Many repackers (FitGirl, Dodi, ElAmigos) use a custom launcher that loads a .bin key file on startup. If you update the game (or download a "new" repack), you need the corresponding key. encryption key bin file gta v download new
Downloading "encryption key bin files" poses significant threats to system integrity. Rockstar updates keys even in minor patches