Here is the full crash report:
---- Minecraft Crash Report ----
// Hey, that tickles! Hehehe!
Time: 20/09/14 7:50 AM
Description: Exception in server tick loop
java.lang.IllegalArgumentException: n must be positive
at java.util.Random.nextInt(Unknown Source)
at net.epicraft.mod.worldgen.EpiCraftWorldGen.addOreSpawn(EpiCraftWorldGen.java:43)
at net.epicraft.mod.worldgen.EpiCraftWorldGen.generateSurface(EpiCraftWorldGen.java:28)
at net.epicraft.mod.worldgen.EpiCraftWorldGen.generate(EpiCraftWorldGen.java:20)
at cpw.mods.fml.common.registry.GameRegistry.generateWorld(GameRegistry.java:106)
at net.minecraft.world.gen.ChunkProviderServer.populate(ChunkProviderServer.java:263)
at net.minecraft.world.chunk.Chunk.populateChunk(Chunk.java:1163)
at net.minecraft.world.gen.ChunkProviderServer.loadChunk(ChunkProviderServer.java:157)
at net.minecraft.server.MinecraftServer.initialWorldChunkLoad(MinecraftServer.java:307)
at net.minecraft.server.integrated.IntegratedServer.loadAllWorlds(IntegratedServer.java:79)
at net.minecraft.server.integrated.IntegratedServer.startServer(IntegratedServer.java:96)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:442)
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:746)
A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------
-- System Details --
Details:
Minecraft Version: 1.7.2
Operating System: Windows 8.1 (amd64) version 6.3
Java Version: 1.7.0_67, Oracle Corporation
Java VM Version: Java HotSpot 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 899731488 bytes (858 MB) / 1037959168 bytes (989 MB) up to 1037959168 bytes (989 MB)
JVM Flags: 3 total; -Xincgc -Xmx1024M -Xms1024M
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
FML: MCP v9.03 FML v7.2.211.1121 Minecraft Forge 10.12.2.1121 4 mods loaded, 4 mods active
mcp{9.03} [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available
FML{7.2.211.1121} [Forge Mod Loader] (forgeSrc-1.7.2-10.12.2.1121.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available
Forge{10.12.2.1121} [Minecraft Forge] (forgeSrc-1.7.2-10.12.2.1121.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available
EpiCraft{v1.0 Beta} [EpiCraft] (bin) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->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 'fml,forge'