The Client running/Unable to proceed with update message appears when you attempt to launch or patch the game while it is already running.
- First, check the system tray to see if the game has been minimized there. This is usually a result of trying to close the game via Alt+F4 or the X in the corner of the window; the only way to properly exit the game is to do so from the in-game menu.
- If the game has not been minimized, go to the Task Manager by pressing Ctrl+Alt+Del and end any instances you see of patcher.exe, launcher.exe, elementclient.exe, and pwprotector.exe, then try again.
- If all else fails, reboot your computer.