From Minecraft Wiki
May 3, 2016
- The game no longer checks https://sessionserver.mojang.com/blockedservers,  as it had begun to in the previous pre-release.
- 1 issue fixed
- From the previous development version
- MC-101545 – Problem with the new pre-release
- Other fixes
- Fixed a potential crash with spreading water or lava.
Video made by slicedlime: