Crash when placing a chain command block with set command

---- Minecraft Crash Report ----
// Oh - I know what I did wrong!

Time: 7/28/18 6:36 PM
Description: Exception while ticking

java.lang.NullPointerException: Exception while ticking
	at bjc.w(SourceFile:119)
	at bjg.j(SourceFile:122)
	at bdg.a(SourceFile:229)
	at bdg.a(SourceFile:120)
	at bdg.a(SourceFile:93)
	at bkw.a(SourceFile:261)
	at tc.b(SourceFile:565)
	at tc$$Lambda$1531/492925641.accept(Unknown Source)
	at ayi.a(SourceFile:79)
	at tc.q_(SourceFile:551)
	at tc.a(SourceFile:215)
	at net.minecraft.server.MinecraftServer.b(SourceFile:728)
	at net.minecraft.server.MinecraftServer.a(SourceFile:661)
	at dga.a(SourceFile:159)
	at net.minecraft.server.MinecraftServer.run(SourceFile:564)
	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 thread
Stacktrace:
	at bjc.w(SourceFile:119)
	at bjg.j(SourceFile:122)
	at bdg.a(SourceFile:229)
	at bdg.a(SourceFile:120)
	at bdg.a(SourceFile:93)
	at bkw.a(SourceFile:261)
	at tc.b(SourceFile:565)
	at tc$$Lambda$1531/492925641.accept(Unknown Source)

-- Block being ticked --
Details:
	Block location: World: (62,1,-26), Chunk: (at 14,0,6 in 3,-2; contains blocks 48,0,-32 to 63,255,-17), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,0,-512 to 511,255,-1)
Stacktrace:
	at ayi.a(SourceFile:79)
	at tc.q_(SourceFile:551)
	at tc.a(SourceFile:215)

-- Affected level --
Details:
	Level name: Redstone
	All players: 1 total; [te[''/33, l='Redstone', x=59.51, y=1.00, z=-24.79]]
	Chunk stats: ServerChunkCache: 458 Drop: 0
	Level seed: 4882365540653810169
	Level generator: ID 01 - flat, ver 0. Features enabled: true
	Level generator options: {biome:"minecraft:the_void",layers:[{block:"minecraft:barrier",height:1}],structures:{decoration:{}}}
	Level spawn location: World: (8,4,8), Chunk: (at 8,0,8 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 13660797 game time, 6000 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.b(SourceFile:728)
	at net.minecraft.server.MinecraftServer.a(SourceFile:661)
	at dga.a(SourceFile:159)
	at net.minecraft.server.MinecraftServer.run(SourceFile:564)
	at java.lang.Thread.run(Thread.java:745)

-- System Details --
Details:
	Minecraft Version: 18w30b
	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: 187640088 bytes (178 MB) / 498393088 bytes (475 MB) up to 1060372480 bytes (1011 MB)
	JVM Flags: 7 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xss1M -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
	Profiler Position: N/A (disabled)
	Player Count: 1 / 8; [te[''/33, l='Redstone', x=59.51, y=1.00, z=-24.79]]
	Data Packs: vanilla
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.