Time: 3/12/19 1:49 AM
Description: Ticking entity

java.lang.IllegalArgumentException
at net.minecraft.util.WeightedRandom.func_76273_a(SourceFile:18)
at net.minecraft.util.WeightedRandom.func_76271_a(SourceFile:37)
at de.teamlapen.vampirism.entity.action.EntityActionHandler.chooseNewAction(EntityActionHandler.java:148)
at de.teamlapen.vampirism.entity.action.EntityActionHandler.updateHandler(EntityActionHandler.java:129)
at de.teamlapen.vampirism.entity.action.EntityActionHandler.handle(EntityActionHandler.java:155)
at de.teamlapen.vampirism.entity.EntityVampirism.func_70636_d(EntityVampirism.java:160)
at de.teamlapen.vampirism.entity.vampire.EntityVampireBase.func_70636_d(EntityVampireBase.java:190)
at de.teamlapen.vampirism.entity.vampire.EntityBasicVampire.func_70636_d(EntityBasicVampire.java:134)
at net.minecraft.entity.EntityLivingBase.func_70071_h_(EntityLivingBase.java:2179)
at net.minecraft.entity.EntityLiving.func_70071_h_(EntityLiving.java:295)
at de.teamlapen.vampirism.entity.EntityVampirism.func_70071_h_(EntityVampirism.java:166)
at de.teamlapen.vampirism.entity.vampire.EntityBasicVampire.func_70071_h_(EntityBasicVampire.java:153)
at net.minecraft.world.World.func_72866_a(World.java:1993)
at net.minecraft.world.WorldServer.func_72866_a(WorldServer.java:832)
at net.minecraft.world.World.func_72870_g(World.java:1955)
at net.minecraft.world.World.func_72939_s(World.java:1759)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:613)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:767)
at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:397)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:668)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526)
at java.lang.Thread.run(Thread.java:748)

A detailed walkthrough of the error, its code path and all known details is as follows:

-- Head --
Thread: Server thread
Stacktrace:
at net.minecraft.util.WeightedRandom.func_76273_a(SourceFile:18)
at net.minecraft.util.WeightedRandom.func_76271_a(SourceFile:37)
at de.teamlapen.vampirism.entity.action.EntityActionHandler.chooseNewAction(EntityActionHandler.java:148)
at de.teamlapen.vampirism.entity.action.EntityActionHandler.updateHandler(EntityActionHandler.java:129)
at de.teamlapen.vampirism.entity.action.EntityActionHandler.handle(EntityActionHandler.java:155)
at de.teamlapen.vampirism.entity.EntityVampirism.func_70636_d(EntityVampirism.java:160)
at de.teamlapen.vampirism.entity.vampire.EntityVampireBase.func_70636_d(EntityVampireBase.java:190)
at de.teamlapen.vampirism.entity.vampire.EntityBasicVampire.func_70636_d(EntityBasicVampire.java:134)
at net.minecraft.entity.EntityLivingBase.func_70071_h_(EntityLivingBase.java:2179)
at net.minecraft.entity.EntityLiving.func_70071_h_(EntityLiving.java:295)
at de.teamlapen.vampirism.entity.EntityVampirism.func_70071_h_(EntityVampirism.java:166)
at de.teamlapen.vampirism.entity.vampire.EntityBasicVampire.func_70071_h_(EntityBasicVampire.java:153)
at net.minecraft.world.World.func_72866_a(World.java:1993)
at net.minecraft.world.WorldServer.func_72866_a(WorldServer.java:832)
at net.minecraft.world.World.func_72870_g(World.java:1955)

Originally posted by @theron61 in #385 (comment)