Mob Spawner block crash - unable to open world after placing mob spawner

Time: 18/03/15 21:08
Description: Ticking block entity

java.lang.IllegalArgumentException: n must be positive
at java.util.Random.nextInt(Unknown Source)
at net.shadowmage.ancientwarfare.structure.tile.SpawnerSettings.updateNormalMode(SpawnerSettings.java:136)
at net.shadowmage.ancientwarfare.structure.tile.SpawnerSettings.onUpdate(SpawnerSettings.java:95)
at net.shadowmage.ancientwarfare.structure.tile.TileAdvancedSpawner.func_145845_h(TileAdvancedSpawner.java:41)
at net.minecraft.world.World.func_72939_s(World.java:1939)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:489)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:636)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:547)
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:111)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:427)
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685)

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 net.shadowmage.ancientwarfare.structure.tile.SpawnerSettings.updateNormalMode(SpawnerSettings.java:136)
at net.shadowmage.ancientwarfare.structure.tile.SpawnerSettings.onUpdate(SpawnerSettings.java:95)
at net.shadowmage.ancientwarfare.structure.tile.TileAdvancedSpawner.func_145845_h(TileAdvancedSpawner.java:41)

-- Block entity being ticked --
Details:
Name: advanced_spawner_tile // net.shadowmage.ancientwarfare.structure.tile.TileAdvancedSpawner
Block type: ID #1282 (tile.advanced_spawner // net.shadowmage.ancientwarfare.structure.block.BlockAdvancedSpawner)
Block data value: 0 / 0x0 / 0b0000
Block location: World: (1916,98,1778), Chunk: (at 12,6,2 in 119,111; contains blocks 1904,0,1776 to 1919,255,1791), Region: (3,3; contains chunks 96,96 to 127,127, blocks 1536,0,1536 to 2047,255,2047)
Actual block type: ID #1282 (tile.advanced_spawner // net.shadowmage.ancientwarfare.structure.block.BlockAdvancedSpawner)
Actual block data value: 0 / 0x0 / 0b0000
Stacktrace:
at net.minecraft.world.World.func_72939_s(World.java:1939)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:489)

-- Affected level --
Details:
Level name: Builder World One Seven
All players: 0 total; []
Chunk stats: ServerChunkCache: 626 Drop: 0
Level seed: -3741348424273070587
Level generator: ID 01 - flat, ver 0. Features enabled: false
Level generator options: 2;7,59x1,3x3,2;1;stronghold,biome_1,village,decoration,dungeon,lake,mineshaft,lava_lake
Level spawn location: World: (1728,72,1762), Chunk: (at 0,4,2 in 108,110; contains blocks 1728,0,1760 to 1743,255,1775), Region: (3,3; contains chunks 96,96 to 127,127, blocks 1536,0,1536 to 2047,255,2047)
Level time: 6140735 game time, 7903310 day time
Level dimension: 0
Level storage version: 0x04ABD - Anvil
Level weather: Rain time: 25089 (now: false), thunder time: 2007 (now: false)
Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:636)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:547)
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:111)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:427)
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685)

-- System Details --
Details:
Minecraft Version: 1.7.10
Operating System: Windows 7 (amd64) version 6.1
Java Version: 1.7.0_09, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 1051554712 bytes (1002 MB) / 2399141888 bytes (2288 MB) up to 3340566528 bytes (3185 MB)
Mod Pack: Unknown / None
LiteLoader Mods: 1 loaded mod(s)
- MAtmos version r28 for 1.7.10
LaunchWrapper: 26 active transformer(s)
- Transformer:

This is due to having both min and max delay the same value.
Easy fix.

Oh! Thanks for that!

Went into world using MCEdit and removed spawner blocks. World now reopens.

Fixed.