custom worlds dont work at all

Minecraft Crash Report ----
// Why did you do that?

Time: 4/24/14 12:41 PM
Description: Exception getting block type in world

java.lang.IllegalArgumentException: n must be positive
at java.util.Random.nextInt(Unknown Source)
at ayy.a(SourceFile:442)
at od.a(SourceFile:175)
at axr.a(SourceFile:847)
at od.c(SourceFile:104)
at od.d(SourceFile:117)
at aky.b(SourceFile:289)
at aky.f(SourceFile:284)
at aky.c(SourceFile:220)
at aky.d(SourceFile:235)
at aky.b(SourceFile:201)
at ayj.a(SourceFile:68)
at oe.b(SourceFile:637)
at oe.a(SourceFile:595)
at cim.a(SourceFile:80)
at cim.g(SourceFile:110)
at net.minecraft.server.MinecraftServer.run(SourceFile:367)
at mu.run(SourceFile:667)

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

– Head –
Stacktrace:
at java.util.Random.nextInt(Unknown Source)
at ayy.a(SourceFile:442)
at od.a(SourceFile:175)
at axr.a(SourceFile:847)
at od.c(SourceFile:104)
at od.d(SourceFile:117)
at aky.b(SourceFile:289)
at aky.f(SourceFile:284)

– Requested block coordinates –
Details:
Found chunk: true
Location: World: (-408,64,137), Chunk: (at 8,4,9 in -26,8; contains blocks -416,0,128 to -401,255,143), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
Stacktrace:
at aky.c(SourceFile:220)
at aky.d(SourceFile:235)
at aky.b(SourceFile:201)
at ayj.a(SourceFile:68)
at oe.b(SourceFile:637)

– Affected level –
Details:
Level name: New Worldweajrbeijt5ei
All players: 0 total; []
Chunk stats: ServerChunkCache: 22 Drop: 0
Level seed: -6689532081749694651
Level generator: ID 04 - customized, ver 0. Features enabled: true
Level generator options: {"coordinateScale":684.412,"heightScale":684.412,"lowerLimitScale":512.0,"upperLimitScale":512.0,"depthNoiseScaleX":200.0,"depthNoiseScaleZ":200.0,"depthNoiseScaleExponent":0.5,"mainNoiseScaleX":80.0,"mainNoiseScaleY":160.0,"mainNoiseScaleZ":80.0,"baseSize":8.5,"stretchY":12.0,"biomeDepthWeight":1.0,"biomeDepthOffset":0.0,"biomeScaleWeight":1.0,"biomeScaleOffset":0.0,"seaLevel":63,"useCaves":true,"useDungeons":true,"dungeonChance":30,"useStrongholds":true,"useVillages":true,"useMineShafts":true,"useTemples":true,"useRavines":true,"useWaterLakes":false,"waterLakeChance":1,"useLavaLakes":false,"lavaLakeChance":1,"useLavaOceans":false,"fixedBiome":-1,"biomeSize":4,"riverSize":1,"dirtSize":33,"dirtCount":10,"dirtMinHeight":0,"dirtMaxHeight":256,"gravelSize":33,"gravelCount":8,"gravelMinHeight":0,"gravelMaxHeight":256,"graniteSize":33,"graniteCount":10,"graniteMinHeight":0,"graniteMaxHeight":80,"dioriteSize":33,"dioriteCount":10,"dioriteMinHeight":0,"dioriteMaxHeight":80,"andesiteSize":33,"andesiteCount":10,"andesiteMinHeight":0,"andesiteMaxHeight":80,"coalSize":17,"coalCount":20,"coalMinHeight":0,"coalMaxHeight":128,"ironSize":9,"ironCount":20,"ironMinHeight":0,"ironMaxHeight":64,"goldSize":9,"goldCount":2,"goldMinHeight":0,"goldMaxHeight":32,"redstoneSize":8,"redstoneCount":8,"redstoneMinHeight":0,"redstoneMaxHeight":16,"diamondSize":8,"diamondCount":1,"diamondMinHeight":0,"diamondMaxHeight":16,"lapisSize":7,"lapisCount":1,"lapisCenterHeight":16,"lapisSpread":16}
Level spawn location: 0.00,0.00,0.00 - World: (0,0,0), Chunk: (at 0,0,0 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: 0 game time, 0 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 oe.a(SourceFile:595)
at cim.a(SourceFile:80)
at cim.g(SourceFile:110)
at net.minecraft.server.MinecraftServer.run(SourceFile:367)
at mu.run(SourceFile:667)

– System Details –
Details:
Minecraft Version: 14w17a
Operating System: Windows 8 (amd64) version 6.2
Java Version: 1.7.0_51, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 158717960 bytes (151 MB) / 240123904 bytes (229 MB) up to 954728448 bytes (910 MB)
JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
IntCache: cache: 1, tcache: 1, allocated: 12, tallocated: 86
Profiler Position: N/A (disabled)
Player Count: 0 / 8; []
Type: Integrated Server (map_client.txt)
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.