Minecraft Forums

I am running 1.7.9 on the latest version of OSX (as of May 27, 2014). As per this forum, the client is full vanilla with no mods or resource packs, though if it matters at all I have used MCEdit 0.1.6 and 0.1.7.1 extensively to work with multiple saves, including the one pertaining to this post. This issue began on a creative map with cheats disabled.

I have been attempting to place a charged creeper spawner at a specific point in the Nether. (For the curious, I am designing a map in the vein of Vechs' Super Hostile series.)

I am attempting to place the spawner atop a block of quartz, with cactus plants one block away on each side, at the coordinates -146 52 157. Below is a screenshot; the lapis block is the point where I would place the spawner.

The exact command that I am using is as follows:
/setblock -146 52 157 mob_spawner 0 replace {EntityID:Creeper,SpawnData:{powered:1}}

I am able to place any other block, including a default spawner. Attempting to place a spawner with any non-default mob specified produces an "empty" spawner; I am not sure if this constitutes some other sort of error.

The first few times I attempted the command, I produced the spawner without incident (the spinning charged creeper appeared inside it as well). However, I accidentally used the wrong coordinates. When I ran the command to set it in the correct coordinates, I had used /setblock to set three or four previous charged creeper spawners during the play session, which I had since destroyed. That was when the game began crashing when I ran the command. I was able to reproduce the crash multiple times (I also reported it using the launcher). Since those crashes, attempting to place a charged creeper spawner anywhere (including in the Overworld) and even on other saves results in a crash.

If I must resort to command-block spawning, I will, but I would not prefer that, as I would like to give players the ability to destroy the spawners. If there is some way I can resolve the problem (or something else that is problematic about the scenario - spawning mechanics are fairly new to me), I would love y'all's input.

Give us the crash log

Time: 5/27/14 10:33 PM
Description: Rendering Block Entity

java.lang.NullPointerException: Rendering Block Entity
at agp.a(SourceFile:110)
at agp.h(SourceFile:236)
at bpb.a(SourceFile:20)
at bpb.a(SourceFile:15)
at bpb.a(SourceFile:10)
at bow.a(SourceFile:100)
at bow.a(SourceFile:92)
at bom.a(SourceFile:383)
at bof.a(SourceFile:994)
at bof.b(SourceFile:814)
at ban.ak(SourceFile:801)
at ban.f(SourceFile:728)
at net.minecraft.client.main.Main.main(SourceFile:148)


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

-- Head --
Stacktrace:
at agp.a(SourceFile:110)
at agp.h(SourceFile:236)
at bpb.a(SourceFile:20)
at bpb.a(SourceFile:15)
at bpb.a(SourceFile:10)

-- Block Entity Details --
Details:
Name: MobSpawner // api
Block type: ID #52 (tile.mobSpawner // alz)
Block data value: 0 / 0x0 / 0b0000
Block location: World: (-146,52,157), Chunk: (at 14,3,13 in -10,9; contains blocks -160,0,144 to -145,255,159), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
Actual block type: ID #52 (tile.mobSpawner // alz)
Actual block data value: 0 / 0x0 / 0b0000
Stacktrace:
at bow.a(SourceFile:100)
at bow.a(SourceFile:92)
at bom.a(SourceFile:383)
at bof.a(SourceFile:994)

-- Affected level --
Details:
Level name: MpServer
All players: 1 total; [blw['Elah806'/0, l='MpServer', x=-146.76, y=53.62, z=155.62]]
Chunk stats: MultiplayerChunkCache: 1089, 1089
Level seed: 0
Level generator: ID 00 - default, ver 1. Features enabled: false
Level generator options:
Level spawn location: World: (8,64,8), Chunk: (at 8,4,8 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: 3765105 game time, 1969 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: 51 total; [ye['Magma Cube'/1220, l='MpServer', x=-69.63, y=24.00, z=138.94], ye['Magma Cube'/1216, l='MpServer', x=-69.63, y=33.00, z=96.63], ye['Magma Cube'/1219, l='MpServer', x=-69.31, y=24.00, z=135.31], yc['Ghast'/1218, l='MpServer', x=-99.53, y=30.41, z=109.03], yg['Zombie Pigman'/1905, l='MpServer', x=-181.53, y=81.00, z=114.94], yg['Zombie Pigman'/1907, l='MpServer', x=-173.06, y=81.00, z=120.06], yg['Zombie Pigman'/1911, l='MpServer', x=-136.50, y=83.00, z=147.59], yg['Zombie Pigman'/2006, l='MpServer', x=-225.66, y=54.00, z=111.44], yg['Zombie Pigman'/2007, l='MpServer', x=-227.78, y=54.00, z=113.44], xw['Blaze'/2010, l='MpServer', x=-130.50, y=60.00, z=106.50], yg['Zombie Pigman'/1737, l='MpServer', x=-205.50, y=61.88, z=153.56], xw['Blaze'/2011, l='MpServer', x=-126.50, y=60.00, z=106.50], yg['Zombie Pigman'/1736, l='MpServer', x=-206.41, y=61.88, z=158.66], yg['Zombie Pigman'/1873, l='MpServer', x=-145.44, y=81.00, z=98.69], yg['Zombie Pigman'/2014, l='MpServer', x=-122.50, y=110.00, z=222.50], yg['Zombie Pigman'/2015, l='MpServer', x=-118.38, y=109.00, z=221.09], yg['Zombie Pigman'/2012, l='MpServer', x=-123.97, y=110.00, z=224.34], yg['Zombie Pigman'/2013, l='MpServer', x=-127.59, y=110.00, z=225.22], yg['Zombie Pigman'/1984, l='MpServer', x=-192.66, y=60.88, z=148.44], yg['Zombie Pigman'/1991, l='MpServer', x=-72.50, y=93.00, z=153.50], yg['Zombie Pigman'/1870, l='MpServer', x=-156.00, y=81.00, z=96.59], yg['Zombie Pigman'/1990, l='MpServer', x=-71.31, y=93.00, z=146.00], yg['Zombie Pigman'/1993, l='MpServer', x=-76.50, y=93.00, z=150.50], yg['Zombie Pigman'/1992, l='MpServer', x=-70.31, y=93.00, z=150.06], yg['Zombie Pigman'/1860, l='MpServer', x=-124.06, y=110.00, z=218.31], yg['Zombie Pigman'/1968, l='MpServer', x=-187.50, y=89.00, z=88.50], blw['Elah806'/0, l='MpServer', x=-146.76, y=53.62, z=155.62], yg['Zombie Pigman'/1983, l='MpServer', x=-201.47, y=60.00, z=131.75], ye['Magma Cube'/1167, l='MpServer', x=-162.26, y=67.00, z=83.69], yg['Zombie Pigman'/1957, l='MpServer', x=-143.50, y=92.00, z=94.50], yg['Zombie Pigman'/1836, l='MpServer', x=-200.56, y=36.00, z=80.06], ye['Magma Cube'/1168, l='MpServer', x=-171.78, y=40.00, z=123.78], yg['Zombie Pigman'/1958, l='MpServer', x=-143.50, y=93.00, z=91.47], ye['Magma Cube'/1172, l='MpServer', x=-144.69, y=25.00, z=103.31], yg['Zombie Pigman'/1952, l='MpServer', x=-112.22, y=35.00, z=164.69], ye['Magma Cube'/1173, l='MpServer', x=-184.38, y=29.00, z=145.60], yg['Zombie Pigman'/1174, l='MpServer', x=-160.44, y=40.00, z=118.03], yg['Zombie Pigman'/1954, l='MpServer', x=-127.31, y=59.00, z=114.38], yc['Ghast'/1175, l='MpServer', x=-146.72, y=54.73, z=111.51], xw['Blaze'/1177, l='MpServer', x=-153.59, y=53.00, z=128.53], yg['Zombie Pigman'/1185, l='MpServer', x=-140.09, y=40.00, z=104.13], yc['Ghast'/1184, l='MpServer', x=-162.61, y=60.59, z=95.25], yg['Zombie Pigman'/1938, l='MpServer', x=-104.50, y=90.00, z=123.50], ye['Magma Cube'/1191, l='MpServer', x=-131.38, y=61.71, z=122.38], yg['Zombie Pigman'/1939, l='MpServer', x=-88.50, y=34.00, z=128.50], yg['Zombie Pigman'/1190, l='MpServer', x=-140.75, y=40.00, z=120.03], yg['Zombie Pigman'/1936, l='MpServer', x=-102.88, y=90.00, z=121.72], ye['Magma Cube'/1189, l='MpServer', x=-139.25, y=40.00, z=123.78], ye['Magma Cube'/1188, l='MpServer', x=-136.20, y=40.00, z=123.78], yg['Zombie Pigman'/1197, l='MpServer', x=-124.03, y=50.00, z=149.28], yg['Zombie Pigman'/1207, l='MpServer', x=-86.38, y=35.00, z=132.28]]
Retry entities: 0 total; []
Server brand: vanilla
Server type: Integrated singleplayer server
Stacktrace:
at blr.a(SourceFile:289)
at ban.b(SourceFile:1972)
at ban.f(SourceFile:737)
at net.minecraft.client.main.Main.main(SourceFile:148)

-- System Details --
Details:
Minecraft Version: 1.7.9
Operating System: Mac OS X (x86_64) version 10.9.2
Java Version: 1.6.0_65, Apple Inc.
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
Memory: 118534688 bytes (113 MB) / 680173568 bytes (648 MB) up to 1065025536 bytes (1015 MB)
JVM Flags: 1 total; -Xmx1G
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
Launched Version: 1.7.9
LWJGL: 2.9.1
OpenGL: Intel HD Graphics 4000 OpenGL Engine GL version 2.1 INTEL-8.24.12, Intel Inc.
GL Caps: Using GL 1.3 multitexturing.
Using framebuffer objects because ARB_framebuffer_object is supported and separate blending is supported.
Anisotropic filtering is supported and maximum anisotropy is 16.
Shaders are available because OpenGL 2.1 is supported.

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)
Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Anisotropic Filtering: Off (1)