Affects Version/s: Minecraft 1.7.2
Fix Version/s: None
Environment:Put your operating system (Windows 7, Windows XP, OSX) and Java version if you know it here
Put the summary of the bug you're having here
What I expected to happen was...:
A fun rollercoaster ride through a cave.
What actually happened was...:
I was stopped by an enormous chunk of land (completely square) that had NOT been there the day before.
Steps to Reproduce:
1. Login to my account
2. Select "World 1"
3. Ride the rollercoaster to the block of land