Put the summary of the bug you're having here

What I expected to happen was...:
After leaving a world by saving and quitting to title and then starting a new world or loading a saved world, the world should appear normal.

What actually happened was...:
The newly created or reloaded world rapidly flashes a series of repeated groups of blocks. Breaking a block will stop flashing until head direction is changed with mouse. Seems to affect all 1.9 snapshots tried on this PC.

Steps to Reproduce:
1. Play in 1.9 pre-4
2. Save and quit to title
3. Either load a save game or create a new world
4. Watch screen go crazy