Ok, I've been playing on my server for quite a while now, and haven't been to the End yet, and when I finally did, the server completely crashed! I was only able to log back in by using MCEdit to move my character back to the overworld.
Crash log: https://www.mediafire.com/file/7aqhnmoaza4b1mx/fml-server-latest_endcrash.log/file
Crash log: https://www.mediafire.com/file/7aqhnmoaza4b1mx/fml-server-latest_endcrash.log/file