When attempting to create a custom worldtype the game gets stuck on "Building Terrain" Minecraft doesn't crash to a crash screen but the console reports a crash.

Custom World Type Preset Code:

{"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":8,"useStrongholds":true,"useVillages":true,"useMineShafts":true,"useTemples":true,"useRavines":true,"useWaterLakes":true,"waterLakeChance":4,"useLavaLakes":true,"lavaLakeChance":4,"useLavaOceans":false,"fixedBiome":-1,"biomeSize":6,"riverSize":2,"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}

Seed: custom

Error Report:
[23:45:44 INFO]: Client> java.lang.IllegalArgumentException: n must be positive
[23:45:44 INFO]: Client> at java.util.Random.nextInt(Random.java:300) ~[?:1.7.0_51]
[23:45:44 INFO]: Client> at ayy.a(SourceFile:442) ~[14w17a.jar:?]
[23:45:44 INFO]: Client> at od.a(SourceFile:175) ~[14w17a.jar:?]
[23:45:44 INFO]: Client> at axr.a(SourceFile:859) ~[14w17a.jar:?]
[23:45:44 INFO]: Client> at od.c(SourceFile:104) ~[14w17a.jar:?]
[23:45:44 INFO]: Client> at net.minecraft.server.MinecraftServer.i(SourceFile:269) ~[14w17a.jar:?]
[23:45:44 INFO]: Client> at cim.a(SourceFile:94) ~[14w17a.jar:?]
[23:45:44 INFO]: Client> at cim.g(SourceFile:110) ~[14w17a.jar:?]
[23:45:44 INFO]: Client> at net.minecraft.server.MinecraftServer.run(SourceFile:367) [14w17a.jar:?]
[23:45:44 INFO]: Client> at mu.run(SourceFile:667) [14w17a.jar:?]
[23:45:44 INFO]: Client> [23:45:44] [Server thread/ERROR]: This crash report has been saved to: C:\Users[REDACTED]\AppData\Roaming\minecraftweekly\crash-reports\crash-2014-04-26_23.45.44-server.txt
[23:45:44 INFO]: Client> [23:45:44] [Server thread/INFO]: Stopping server
[23:45:44 INFO]: Client> [23:45:44] [Server thread/INFO]: Saving players
[23:45:44 INFO]: Client> [23:45:44] [Server thread/INFO]: Saving worlds
[23:45:44 INFO]: Client> [23:45:44] [Server thread/INFO]: Saving chunks for level 'D8WG1_5'/Overworld
[23:45:44 INFO]: Client> [23:45:44] [Server thread/INFO]: Saving chunks for level 'D8WG1_5'/Nether
[23:45:44 INFO]: Client> [23:45:44] [Server thread/INFO]: Saving chunks for level 'D8WG1_5'/The End