17w17a Crashes without strongholds

As of 17w17a, custom worlds set to generate without strongholds either A: Crash in single player or B: Kick the player in Multiplayer. Easily reproduced by making a custom world and turning off stronghold generation.

---- Minecraft Crash Report ----
// Sorry :(

Time: 4/26/17 6:27 PM
Description: Ticking player

java.lang.NullPointerException: Ticking player
	at bau.a(SourceFile:188)
	at bau.b(SourceFile:135)
	at aye.a(SourceFile:535)
	at nr.a(SourceFile:227)
	at am$b.a(SourceFile:118)
	at am$a.a(SourceFile:148)
	at am.a(SourceFile:85)
	at nu.k_(SourceFile:390)
	at oe.G_(SourceFile:182)
	at gf.a(SourceFile:231)
	at od.c(SourceFile:187)
	at net.minecraft.server.MinecraftServer.D(SourceFile:652)
	at net.minecraft.server.MinecraftServer.C(SourceFile:562)
	at cgb.C(SourceFile:154)
	at net.minecraft.server.MinecraftServer.run(SourceFile:466)
	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: Client thread
Stacktrace:
	at bau.a(SourceFile:188)
	at bau.b(SourceFile:135)
	at aye.a(SourceFile:535)
	at nr.a(SourceFile:227)
	at am$b.a(SourceFile:118)
	at am$a.a(SourceFile:148)
	at am.a(SourceFile:85)

-- Player being ticked --
Details:
	Entity Type: null (nu)
	Entity ID: 13013
	Entity Name: Sledgomatic
	Entity's Exact location: -60.52, 98.92, 10.33
	Entity's Block location: World: (-61,98,10), Chunk: (at 3,6,10 in -4,0; contains blocks -64,0,0 to -49,255,15), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Entity's Momentum: 0.00, -0.16, 0.00
	Entity's Passengers: []
	Entity's Vehicle: ~~ERROR~~ NullPointerException: null
Stacktrace:
	at nu.k_(SourceFile:390)
	at oe.G_(SourceFile:182)
	at gf.a(SourceFile:231)

-- Ticking connection --
Details:
	Connection: gf@656910ec
Stacktrace:
	at od.c(SourceFile:187)
	at net.minecraft.server.MinecraftServer.D(SourceFile:652)
	at net.minecraft.server.MinecraftServer.C(SourceFile:562)
	at cgb.C(SourceFile:154)
	at net.minecraft.server.MinecraftServer.run(SourceFile:466)
	at java.lang.Thread.run(Thread.java:745)

-- System Details --
Details:
	Minecraft Version: 17w17a
	Operating System: Windows 10 (amd64) version 10.0
	Java Version: 1.8.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 271294296 bytes (258 MB) / 568250368 bytes (541 MB) up to 3207856128 bytes (3059 MB)
	JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx3G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Profiler Position: N/A (disabled)
	Player Count: 1 / 8; [nu['Sledgomatic'/13013, l='No stronghold test', x=-60.52, y=98.92, z=10.33]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.
#@!@# Game crashed! Crash report saved to: #@!@# C:\Users\Sledge\AppData\Roaming\.minecraftSnap\crash-reports\crash-2017-04-26_18.27.28-server.txt
  <log4j:Event logger="net.minecraft.server.MinecraftServer" timestamp="1493256448453" level="INFO" thread="Client Shutdown Thread">
    <log4j:Message><![CDATA[Stopping server]]></log4j:Message>
  </log4j:Event>