Entering Worlds

When my friend and I enter a world, he had this dirt screen show up, then we would have to restart minecraft. It happens when he joins my lan and his worlds.

*He uses a old computer, Windows 7 and his C drive has problems. It always is full. No matter what I do to clean it, there will be no memory left.
I have a mac book air, which is perfectly fine, nothing is wrong but the dirt screen still shows up.

The issue is defiantly the snapshots problems,
hope this helped

It happens only in this snapshot