Game Launcher Says "Patcher has failed"

The patcher sometimes fails if it can't maintain a solid internet connection to download the game. Open the 'Settings' panel in the game launcher (click the gear button in top-left) and click the 'Wrench' button. If that doesn't work, try the 'Redownload' button (circling arrows). If that doesn't work, send us a bug report with the player log.