java.lang.IllegalArgumentException: bound must be positive at java.util.Random.nextInt(Unknown Source) at com.flansmod.apocalypse.common.FlansModLootGenerator.getRandomUnloadedGun(FlansModLootGenerator.java:135) at com.flansmod.apocalypse.common.FlansModLootGenerator.getRandomLoadedGun(FlansModLootGenerator.java:112) at com.flansmod.apocalypse.common.FlansModLootGenerator.addRandomLoot(FlansModLootGenerator.java:147) at com.flansmod.apocalypse.common.world.buildings.WorldGenSkeleton.func_180709_b(WorldGenSkeleton.java:25) at com.flansmod.apocalypse.common.world.ChunkProviderApocalypse.func_73153_a(ChunkProviderApocalypse.java:262) at org.spongepowered.mod.world.gen.SpongeChunkProviderForge.func_73153_a(SpongeChunkProviderForge.java:174) at net.minecraft.world.gen.ChunkProviderServer.func_73153_a(ChunkProviderServer.java:269) at net.minecraft.world.chunk.Chunk.func_76624_a(Chunk.java:1126) at net.minecraft.world.gen.ChunkProviderServer.originalLoadChunk(ChunkProviderServer.java:180) at net.minecraft.world.gen.ChunkProviderServer.loadChunk(ChunkProviderServer.java:122) at net.minecraft.world.gen.ChunkProviderServer.func_73158_c(ChunkProviderServer.java:92) at net.minecraft.server.MinecraftServer.prepareSpawnArea(MinecraftServer.java:596) at java.lang.Iterable.forEach(Unknown Source) at net.minecraft.server.MinecraftServer.func_71222_d(MinecraftServer.java:575) at net.minecraft.server.MinecraftServer.func_71247_a(MinecraftServer.java:458) at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:259) at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:438) at java.lang.Thread.run(Unknown Source)

Seems like Apocalypse 1.0 is incompatible with sponge.