[MC-143819] Game can get stuck at 0% when opening world

The bug

When I opened a world (was opened correctly in the same version already), the loading screen got stuck at 0%, but the window remained responsive.

The last logged lines were:

17:47:56	dsa	Starting integrated minecraft server version 19w06a
17:47:56	dsa	Generating keypair
17:48:12	wu	Reloading ResourceManager: Default, test
17:48:28	azx	Loaded 6 recipes
17:48:33	qq	Loaded 2 custom command functions
17:48:39	o	Loaded 800 advancements
17:48:43	net.minecraft.server.MinecraftServer	Preparing start region for dimension minecraft:overworld

Thread dumps are attached.