We are aware of a rare issue where the game may crash after the first combat with the Bullymongs in Windshear Wastes while in 4-player split-screen. Our engineers are aware of this issue and are investigating possible resolutions to be included in a future update. In the meantime, you may avoid this issue by starting split-screen from the following checkpoint. If you have any questions about this, please submit a support ticket at http://support.gearboxsoftware.com.