I'm playing the beta in multiplayer. This is all that led up to the consistent crashing: we just beat the ender dragon, and all went through to the end city place, one of the four of us died, respawned at the portal in the stronghold, broke his bed, went back into the end, and died again, and my game (the host) crashed. We reloaded, and it keeps crashing every time he tries to respawn or travel back to the over world through the portal. He's essentially trapped in the end now.