[19:41:05] [Server thread/ERROR]: Could not pass event ItemSpawnEvent to AntiShare v5.5.2
org.bukkit.event.EventException
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:427) ~[spigot.jar:git-Spigot-1231]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot.jar:git-Spigot-1231]
at org.bukkit.plugin.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:30) ~[spigot.jar:git-Spigot-1231]
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:482) [spigot.jar:git-Spigot-1231]
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:467) [spigot.jar:git-Spigot-1231]
at org.bukkit.craftbukkit.v1_7_R1.event.CraftEventFactory.callItemSpawnEvent(CraftEventFactory.java:285) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.World.addEntity(World.java:955) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.World.addEntity(World.java:924) [spigot.jar:git-Spigot-1231]
at org.bukkit.craftbukkit.v1_7_R1.CraftWorld.dropItem(CraftWorld.java:301) [spigot.jar:git-Spigot-1231]
at org.bukkit.craftbukkit.v1_7_R1.CraftWorld.dropItemNaturally(CraftWorld.java:315) [spigot.jar:git-Spigot-1231]
at org.bukkit.craftbukkit.v1_7_R1.event.CraftEventFactory.callEntityDeathEvent(CraftEventFactory.java:352) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.EntityInsentient.dropDeathLoot(EntityInsentient.java:202) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.EntityLiving.die(EntityLiving.java:790) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.EntityLiving.damageEntity(EntityLiving.java:739) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.EntityLiving.b(EntityLiving.java:878) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.Entity.a(Entity.java:809) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.EntityLiving.a(EntityLiving.java:150) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.Entity.move(Entity.java:636) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.EntityLiving.e(EntityLiving.java:1217) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.EntityLiving.e(EntityLiving.java:1473) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.EntityInsentient.e(EntityInsentient.java:306) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.EntityLiving.h(EntityLiving.java:1306) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.EntityInsentient.h(EntityInsentient.java:150) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.EntitySlime.h(EntitySlime.java:73) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.World.entityJoinedWorld(World.java:1469) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.World.playerJoinedWorld(World.java:1445) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.World.tickEntities(World.java:1314) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.WorldServer.tickEntities(WorldServer.java:509) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:636) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:273) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:540) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:446) [spigot.jar:git-Spigot-1231]
at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [spigot.jar:git-Spigot-1231]
Caused by: java.lang.NullPointerException
at com.turt2live.antishare.manager.BlockManager.getType(BlockManager.java:188) ~[?:?]
at com.turt2live.antishare.ASListener.onItemSpawn(ASListener.java:551) ~[?:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0_45]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) ~[?:1.7.0_45]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.7.0_45]
at java.lang.reflect.Method.invoke(Method.java:606) ~[?:1.7.0_45]
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425) ~[spigot.jar:git-Spigot-1231]
... 32 more

Any information on what caused this error? I can't replicate it