Block of land appeared out of nowhere

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