Fatal game crash - Polar Bear vehicle NPE

Can also be caused by Pillagers when a raid is spawned, again preventing the world from loading.

---- Minecraft Crash Report ----
// Don't do that.

Time: 6/12/18, 8:35 PM
Description: Ticking entity

java.lang.NullPointerException: Ticking entity
	at aro.a(SourceFile:108)
	at arn.k(SourceFile:61)
	at agt.T_(SourceFile:1886)
	at agu.T_(SourceFile:285)
	at apj.T_(SourceFile:45)
	at bas.a(SourceFile:1165)
	at uk.a(SourceFile:395)
	at bas.g(SourceFile:1145)
	at bas.m_(SourceFile:1027)
	at uk.m_(SourceFile:311)
	at net.minecraft.server.MinecraftServer.b(SourceFile:787)
	at net.minecraft.server.MinecraftServer.a(SourceFile:716)
	at doq.a(SourceFile:128)
	at net.minecraft.server.MinecraftServer.run(SourceFile:582)
	at java.base/java.lang.Thread.run(Thread.java:834)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Thread: Server thread
Stacktrace:
	at aro.a(SourceFile:108)
	at arn.k(SourceFile:61)
	at agt.T_(SourceFile:1886)
	at agu.T_(SourceFile:285)
	at apj.T_(SourceFile:45)
	at bas.a(SourceFile:1165)
	at uk.a(SourceFile:395)
	at bas.g(SourceFile:1145)

-- Entity being ticked --
Details:
	Entity Type: minecraft:pillager (apn)
	Entity ID: 194
	Entity Name: Pillager
	Entity's Exact location: -340.51, 71.00, 1019.77
	Entity's Block location: World: (-341,71,1019), Chunk: (at 11,4,11 in -22,63; contains blocks -352,0,1008 to -337,255,1023), Region: (-1,1; contains chunks -32,32 to -1,63, blocks -512,0,512 to -1,255,1023)
	Entity's Momentum: 0.00, -0.08, -0.14
	Entity's Passengers: []
	Entity's Vehicle: ~~ERROR~~ NullPointerException: null
Stacktrace:
	at bas.m_(SourceFile:1027)
	at uk.m_(SourceFile:311)

-- Affected level --
Details:
	Level name: Snapshot
	All players: 1 total; [um['hemebond'/180, l='Snapshot', x=-351.65, y=70.00, z=1023.13]]
	Chunk stats: ServerChunkCache: 4050
	Level seed: -1129550582963982400
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options: {}
	Level spawn location: World: (240,70,-192), Chunk: (at 0,4,0 in 15,-12; contains blocks 240,0,-192 to 255,255,-177), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,0,-512 to 511,255,-1)
	Level time: 5932600 game time, 3224771 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 18160 (now: false), thunder time: 43631 (now: false)
	Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.b(SourceFile:787)
	at net.minecraft.server.MinecraftServer.a(SourceFile:716)
	at doq.a(SourceFile:128)
	at net.minecraft.server.MinecraftServer.run(SourceFile:582)
	at java.base/java.lang.Thread.run(Thread.java:834)

-- System Details --
Details:
	Minecraft Version: 18w49a
	Operating System: Linux (amd64) version 4.18.0-2-amd64
	Java Version: 11.0.1, Oracle Corporation
	Java VM Version: OpenJDK 64-Bit Server VM (mixed mode, sharing), Oracle Corporation
	Memory: 721410960 bytes (687 MB) / 1375731712 bytes (1312 MB) up to 2147483648 bytes (2048 MB)
	JVM Flags: 7 total; -Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
	Player Count: 1 / 8; [um['hemebond'/180, l='Snapshot', x=-351.65, y=70.00, z=1023.13]]
	Data Packs: vanilla
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.

It doesn't seem to happen to me after i tested it. All i did though was spawn one with an egg and than summoned one with a command

Updated to 18w50a and my world is now loading, and the pillager raid is still there.

Update: Just crashed again with the same error during a raid. Was thankfully able to reload the world.

Occurs in 19w03c

Not sure if this is related to here or not, but the new Trader Llama causes a NPE Ticking Entity server crash consistently.

Still happens as of 19w07a

Other entity's vehicle NPE crashes in MC-143404