[MC-124123] Crash upon loading world: Non [a-z0-9/._-] character in path of location: minecraft:Zombie

The bug

Frequently when I go onto a singleplayer world in 18w02a, my game crashes.

How to reproduce

Occurs when entity id contains capital letters in the SpawnData tag.

Use the command

/setblock ~ ~1 ~ minecraft:mob_spawner{SpawnData:{id:"Husk"}} replace

Another world download provided by Brandon in ~~MC-125703~~: http://www.mediafire.com/file/kkpj786xmlsem3g/Chew%27s_Minecraft_World.zip

Crash report

18w02a: crash-2018-01-12_15.57.03-server.txt

Description: Exception ticking world

g: Non [a-z0-9/._-] character in path of location: minecraft:Zombie
	at ns.<init>(SourceFile:36)
	at ns.<init>(SourceFile:41)
	at aru.g(SourceFile:42)
	at aru.b(SourceFile:185)
	at bbf.a(SourceFile:86)
	at bbf.Q_(SourceFile:104)
	at jm.<init>(SourceFile:52)
	at rt.b(SourceFile:105)
	at ru.c(SourceFile:165)
	at ro.d(SourceFile:219)
	at net.minecraft.server.MinecraftServer.w(SourceFile:673)
	at net.minecraft.server.MinecraftServer.v(SourceFile:606)
	at cmj.v(SourceFile:152)
	at net.minecraft.server.MinecraftServer.run(SourceFile:511)
	at java.lang.Thread.run(Thread.java:745)