The bug

I'm just moving around in my jungle world while trying to record a youtube video.
Windows that were open are chrome, obs, sticky notes, streamlabs obs, and the minecraft launcher, as well as the game
The game will crash after moving around a little bit.

Very lagging in the jungle, the log repeatedly prints the message "Ticking entity", and finally crashes the game.

Reproduce

1. Create a superflat world of jungle biome, and fly freely on the world.

   minecraft:bedrock,63*minecraft:dirt,minecraft:grass_block;minecraft:jungle;biome_1,decoration,lake,lava_lake
   

2. Using spawn eggs to spawn very many parrots.
3. Use the following command

   /tp @e[type=parrot] @p
   

Here is the crash report:

19w40a: crash-2019-10-03_23.59.03-client.txt

Description: Ticking entity

java.lang.NullPointerException: Ticking entity
	at atd.a(SourceFile:407)
	at akm.ab(SourceFile:301)
	at akn.ab(SourceFile:228)
	at akd.h(SourceFile:399)
	at akm.h(SourceFile:2059)
	at akn.h(SourceFile:295)
	at atk.h(SourceFile:34)
	at dmr.a(SourceFile:165)
	at bjk.a(SourceFile:648)
	at dmr.g(SourceFile:136)
	at das.n(SourceFile:1389)
	at das.d(SourceFile:907)
	at das.b(SourceFile:569)
	at net.minecraft.client.main.Main.main(SourceFile:199)