crashed when looked to a cow in the window

Put the summary of the bug you're having here

What I expected to happen was...:
I thought the cow would simply walk away

What actually happened was...:
minecraft simply closed with the crash report when i looked to a cow and a skeleton near it

Steps to Reproduce:
1.i made a trade with a villager
2. looked to a cow in the window
3. apparently there was a skeleton near it and then crashed