If you punch a baby polar bear in survival the game will crash while ticking entity. 

What i expected to happen was l when i punched the babby plar bear for it to run away.

What happened the game crashed quickly after.

this is the crash log cause i can't post the file for some reason 

— Minecraft Crash Report ------- Minecraft Crash Report ----// Don't be sad, have a hug! <3
Time: 2/15/19 12:27 AMDescription: Ticking entity
java.lang.NullPointerException: Ticking entity at aln.g(SourceFile:81) at anh$c.c(SourceFile:220) at ajt.a(SourceFile:102) at ahv.cU(SourceFile:604) at ahu.k(SourceFile:2049) at ahv.k(SourceFile:473) at ahj.k(SourceFile:140) at amt.k(SourceFile:46) at ahu.h(SourceFile:1900) at ahv.h(SourceFile:284) at anh.h(SourceFile:149) at bdb.a(SourceFile:647) at uu.a(SourceFile:652) at uu.k_(SourceFile:449) at net.minecraft.server.MinecraftServer.b(SourceFile:844) at net.minecraft.server.MinecraftServer.a(SourceFile:775) at dsk.a(SourceFile:128) at net.minecraft.server.MinecraftServer.run(SourceFile:633) at java.lang.Thread.run(Thread.java:745)

A detailed walkthrough of the error, its code path and all known details is as follows:---------------------------------------------------------------------------------------
– Head --Thread: Server threadStacktrace: at aln.g(SourceFile:81) at anh$c.c(SourceFile:220) at ajt.a(SourceFile:102) at ahv.cU(SourceFile:604) at ahu.k(SourceFile:2049) at ahv.k(SourceFile:473) at ahj.k(SourceFile:140) at amt.k(SourceFile:46) at ahu.h(SourceFile:1900) at ahv.h(SourceFile:284) at anh.h(SourceFile:149) at bdb.a(SourceFile:647) at uu.a(SourceFile:652)
– Entity being ticked --Details: Entity Type: minecraft:polar_bear (anh) Entity ID: 10 Entity Name: Polar Bear Entity's Exact location: 204.68, 64.64, 185.39 Entity's Block location: World: (204,64,185), Chunk: (at 12,4,9 in 12,11; contains blocks 192,0,176 to 207,255,191), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511) Entity's Momentum: 0.00, 0.19, 0.13 Entity's Passengers: [] Entity's Vehicle: ~_ERROR~ NullPointerException: nullStacktrace: at uu.k_(SourceFile:449)
– Affected level --Details: Level name: New World All players: 1 total; [uv['JackTheDog2008'/255, l='New World', x=202.73, y=64.00, z=183.34]] Chunk stats: ServerChunkCache: 2325 Level seed: 7807882043939241334 Level generator: ID 00 - default, ver 1. Features enabled: true Level generator options: {} Level spawn location: World: (208,64,176), Chunk: (at 0,4,0 in 13,11; contains blocks 208,0,176 to 223,255,191), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511) Level time: 957 game time, 957 day time Level dimension: 0 Level storage version: 0x04ABD - Anvil Level weather: Rain time: 45893 (now: false), thunder time: 100436 (now: false) Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: trueStacktrace: at net.minecraft.server.MinecraftServer.b(SourceFile:844) at net.minecraft.server.MinecraftServer.a(SourceFile:775) at dsk.a(SourceFile:128) at net.minecraft.server.MinecraftServer.run(SourceFile:633) at java.lang.Thread.run(Thread.java:745)
– System Details --Details: Minecraft Version: 19w07a Operating System: Windows 10 (amd64) version 10.0 Java Version: 1.8.0_51, Oracle Corporation Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation Memory: 841142504 bytes (802 MB) / 2113929216 bytes (2016 MB) up to 2147483648 bytes (2048 MB) JVM Flags: 9 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xss1M -Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M Player Count: 1 / 8; [uv['JackTheDog2008'/255, l='New World', x=202.73, y=64.00, z=183.34]] Data Packs: vanilla Type: Integrated Server (map_client.txt) Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.