Paintings and item frames that are invulnerable crash the game if chunks they are in are loaded.
How to reproduce:
1. Launch the attached world on version 1.7.9
2. You can see there are paintings and item frames that are unbreakable as they have Invulnerable tag. Try punching them to make sure
3. Now load this world on 14w18a
4. Game will crash as soon as the world loads