Unexpected Game Crash after loading a level

Put the summary of the bug you're having here

What I expected to happen was: The level should be playable and I coult continue playing in my survival world
Describe what you thought should happen here

What actually happened was: the game crashed instandly - a crash report has been created
Describe what happened here

Steps to Reproduce:
1. Open the new Launcher
2. Go to Singleplayer
3. Select a level
4. Open it up
5. CRASH!