Player cannot move, blocks do not disappear when mined, player stuck bouncing in place.

Put the summary of the bug you're having here

What I expected to happen was...:
Player should be able to move around in 3 dimensions. Blocks should go away AND produce blocks for inventory when mined.

What actually happened was...:
I dug a hole and jumped down, then began experiencing glitches where I was stuck bouncing in place and could not extract myself or interact with the environment.

Steps to Reproduce:
1. Create new world
2. Find soft ground and dig a hole
3. Send crash report to JIRA.