Why is Rainbow Six Siege broken on PC? (BattlEye fails to initialize, game won't launch)
Game launches the Ubisoft Connect overlay but closes immediately, sometimes with a BattlEye-related error. BattlEye's service can fail to start if Windows updates change driver signing requirements or if a conflicting security tool blocks its service. Fix: Restart your PC — BattlEye's service often needs a fresh boot after a Windows update, similar to other kernel-level anti-cheats.