My game would crash while I was in the End, and this happened on my private server and on singleplayer as well. My server was also running the latest snapshot (14w03b) I was not able to connect back to my server, and cause me to set it back to 14w02c.
This bug has allready been very reported. Take a look at this link and check if it matches your issue. https://mojang.atlassian.net/browse/MC-45071