Crash when going outside height limit or into the void with F3

Right, my client crashes when I fall out of the world from the stone platform in the superflat world.

Confirmed for 15w37a

Also happens while opening debug screen while too high( > 255 blocks)

Do you mean "Crash when going outside height limit with f3"?

Happens when flying and lowering yourself slowly using shift. Lowest y co-ord I got was about 0.12 before the crash.

Affects 16w15b, please reopen this ticket!
Stacktrace down below, unmodded, vanilla, single player world, no resourcepacks, super flat world.

---- Minecraft Crash Report ----
// Ouch. That hurt :(

Time: 4/16/16 1:03 PM
Description: Unexpected error

java.lang.ArrayIndexOutOfBoundsException: 16
	at ase.a(SourceFile:554)
	at bcz.b(SourceFile:158)
	at bcz.a(SourceFile:70)
	at bcz.a(SourceFile:53)
	at bcr.a(SourceFile:223)
	at bnd.a(SourceFile:1038)
	at bcc.av(SourceFile:986)
	at bcc.a(SourceFile:393)
	at net.minecraft.client.main.Main.main(SourceFile:124)


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

-- Head --
Stacktrace:
	at ase.a(SourceFile:554)
	at bcz.b(SourceFile:158)
	at bcz.a(SourceFile:70)
	at bcz.a(SourceFile:53)
	at bcr.a(SourceFile:223)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bmq['Anonymous'/2, l='MpServer', x=1490.50, y=256.00, z=694.50]]
	Chunk stats: MultiplayerChunkCache: 961, 961
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (1490,4,688), Chunk: (at 2,0,0 in 93,43; contains blocks 1488,0,688 to 1503,255,703), Region: (2,1; contains chunks 64,32 to 95,63, blocks 1024,0,512 to 1535,255,1023)
	Level time: 2729 game time, 6000 day time
	Level dimension: 0
	Level storage version: 0x00000 - Unknown?
	Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false
	Forced entities: 1 total; [bmq['Anonymous'/2, l='MpServer', x=1490.50, y=256.00, z=694.50]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at bkr.a(SourceFile:365)
	at bcc.b(SourceFile:2516)
	at bcc.a(SourceFile:407)
	at net.minecraft.client.main.Main.main(SourceFile:124)

-- System Details --
Details:
	Minecraft Version: 16w15b
	Operating System: Mac OS X (x86_64) version 10.11.4
	Java Version: 1.8.0_74, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 333757280 bytes (318 MB) / 715816960 bytes (682 MB) up to 1060372480 bytes (1011 MB)
	JVM Flags: 5 total; -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 16w15b
	LWJGL: 2.9.2
	OpenGL: Intel HD Graphics 5000 OpenGL Engine GL version 2.1 INTEL-10.14.58, Intel Inc.
	GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because ARB_framebuffer_object is supported and separate blending is supported.
Shaders are available because OpenGL 2.1 is supported.
VBOs are available because OpenGL 1.5 is supported.

	Using VBOs: Yes
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Packs: 
	Current Language: English (US)
	Profiler Position: N/A (disabled)
	CPU: bcc$7@7923cb8d

Confirmed it's back in 16w15b.

Is this really the same issue when in two versions so far away from each other?

Yup, look at the stack traces.

Fixed again in 1.9.3 Pre-Release 1.