In March 2021, Rockstar Games officially updated Grand Theft Auto IV to version 1.2.0.43 (also known as the "Rockstar Launcher Update" or "Patch 2020/2021"). This update:
If you encounter this error today, know that it is solvable. It will take an hour of reading, a few downloads from trusted GitHub repositories, and a lot of patience. But soon, Niko will be back, bowling with Roman, driving through a rainy Broker at 3 AM, and you won’t see a single error code. gta iv 12059 2021
The number refers to version Grand Theft Auto IV: The Complete Edition In March 2021, Rockstar Games officially updated Grand
So 12059 = the Steam depot for the post-GFWL, single-player-only GTA IV. In March 2021
In short,