Blaze cause Ticking Entity crash on SMP server.

Not really sure what happened. I was AFKing at my Blaze farm, and got disconnected with "Server closed" message. I can bring the server back up just fine, and other players can connect and play, but as soon as I connect, or other players get close enough to load the Blaze farm, the server crashes again almost immediately.

This blaze farm was working fine yesterday on the same version (15w45a), so I have no idea what might be different now.

Crash report attached.