My modpack will not load worlds unless I put the mods in the folders manually. It sucks because if I want to have people download it, it doesn't load or generate worlds. It just freezes.
[EDIT]
Crash Report:
---- Minecraft Crash Report ----
// Ouch. That hurt
Time: 3/23/13 8:15 PM
Description: Exception in server tick loop
java.lang.IllegalArgumentException: n must be positive
at java.util.Random.nextInt(Unknown Source)
at chocolate.mods.BD.WorldGenerator.generateBigDungeon(WorldGenerator.java:153)
at chocolate.mods.BD.WorldGenerator.generateSurface(WorldGenerator.java:121)
at chocolate.mods.BD.WorldGenerator.generate(WorldGenerator.java:43)
at cpw.mods.fml.common.registry.GameRegistry.generateWorld(GameRegistry.java:90)
at im.a(ChunkProviderServer.java:259)
at zz.a(Chunk.java:1258)
at im.c(ChunkProviderServer.java:153)
at net.minecraft.server.MinecraftServer.e(MinecraftServer.java:310)
at bdz.a(IntegratedServer.java:84)
at bdz.c(IntegratedServer.java:100)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:458)
at fy.run(SourceFile:849)
A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------
-- System Details --
Details:
Minecraft Version: 1.4.7
Operating System: Windows 7 (amd64) version 6.1
Java Version: 1.7.0_13, Oracle Corporation
Java VM Version: Java HotSpot 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 419744816 bytes (400 MB) / 598999040 bytes (571 MB) up to 1908932608 bytes (1820 MB)
JVM Flags: 1 total; -Xmx2048m
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Suspicious classes: FML and Forge are installed
IntCache: cache: 0, tcache: 0, allocated: 3, tallocated: 63
FML: MCP v7.26 FML v4.7.4.520 Minecraft Forge 6.6.0.497 18 mods loaded, 18 mods active
mcp [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
FML [Forge Mod Loader] (coremods) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
Forge [Minecraft Forge] (coremods) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
GuiAPI [GuiAPI] (GuiAPI-0.15.2-1.4.6.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
mod_ReiMinimap [mod_ReiMinimap] ([1.4.7]ReiMinimap_v3.2_06.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
mod_Armor [mod_Armor] (Armor-Stand-Mod-1.4.6.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
BattleTowers [battle Towers] (BattleTowers_1.4.6.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
BetterDungeons [better dungeons] (BetterDungeons.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
Lepko-EasyCrafting [Easy Crafting] (Easy-Crafting-Mod-1.4.7.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
mod_InvTweaks [inventory Tweaks] (InvTweaks-1.50-1.4.7.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
Millenaire [Millénaire] (millenaire4.3.2.1.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
AS_Minions [Minions] (Minions_1.4.6.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
RopesPlus [Ropes+] (RopePlus_1.4.6.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
mod_Shelf [mod_Shelf] (Shelf-Mod-1.4.6.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
Steamship [steamship] (Steamship.v1.2-1.4.6.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
Thaumcraft [Thaumcraft] (Thaumcraft3.0.3.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
AS_UpdateCheck [AtomicStryker Update Check Mod] (UpdateCheckerMod_1.4.6.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
weaponmod [balkon's WeaponMod] (WeaponMod.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available
Profiler Position: N/A (disabled)
Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Player Count: 0 / 8; []
Type: Integrated Server (map_client.txt)
Is Modded: Definitely; Client brand changed to 'forge,fml'