cant pick up items, enemies and other things freeze

Put the summary of the bug you're having here

What I expected to happen was...:
i wanted to pick up my items after dying 

What actually happened was...:
nothing happened when i walked over them, sheep and skeletons froze

Steps to Reproduce:
1. die(by drowned, skeleton or creeper explosion)
2. you must be far away from death point, walk to collect items (i had to swim)
3. try to pick up items. things just freeze