Far Cry 3 relies on specific versions of the Microsoft Visual C++ Redistributable (specifically the 2010 and 2012 packages). If these are missing or corrupted, the launcher fails to initialize the game engine.
If running as an administrator doesn't work, the most reliable fix is performing a clean reinstallation of the launcher. A simple uninstall may leave behind files and registry entries that recreate the problem. A clean removal is necessary. far cry 3 ubisoft game launcher error code 2