Update: After persistent crashes, Snapshot World has been restored to 14w47c (last known stable version). A crash report has been submitted to Mojang. It seems to be related to a double wooden slab. Hopefully the issue isn’t in 14w47c.
Snapshot server updated to 15w49a, mc1.gamergeeks.nz:25571
Remember snapshots may not be stable, and everything may disappear into a black hole!