The bug:

When using the new Minecraft Launcher, the game crashes after reaching 100% when loading of creating worlds. This only seems to me the case in version 1.17 and over, including the new snapshots. Versions 1.16.5 work, as well as using the old launcher with version 1.17.1.

To reproduce:

Start the new Minecraft launcher

Start an unmodified Version newer than 1.17

Create / load a world

The game will crash once the loading indicator reaches 100% (Crash Log attached)

Expected result:

The game should load the world correctly