Far Cry 3 Ubisoft Game Launcher | Error Code 2

Error Code 2 can sometimes occur if your Antivirus software has quarantined a file during an update, falsely identifying it as a threat.

Navigate to your Far Cry 3 installation directory. For Steam users, the default path is: ...\Steam\steamapps\common\Far Cry 3\Support\GameLauncher

The Ubisoft Connect client is not installed or is severely outdated.

The absolute baseline fix is removing the legacy Uplay folder structure entirely.