[19:53:56] [Server thread/ERROR]: Could not pass event ArtificialBlockPlaceEvent to StackableItems v0.9.5
org.bukkit.event.EventException
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:320) ~[craftbukkit.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[craftbukkit.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
    at org.bukkit.plugin.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:47) ~[craftbukkit.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:487) [craftbukkit.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:472) [craftbukkit.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
    at me.lyneira.MachinaCore.EventSimulator.blockPlace(EventSimulator.java:51) [MachinaCore.jar:?]
    at me.lyneira.MachinaCore.Movable.canPlace(Movable.java:341) [MachinaCore.jar:?]
    at me.lyneira.MachinaBuilder.BlockDropperBuilder.access$1(BlockDropperBuilder.java:1) [MachinaBuilder.jar:?]
    at me.lyneira.MachinaBuilder.BlockDropperBuilder$Build.run(BlockDropperBuilder.java:72) [MachinaBuilder.jar:?]
    at me.lyneira.MachinaBuilder.Builder.heartBeat(Builder.java:141) [MachinaBuilder.jar:?]
    at me.lyneira.MachinaCore.MachinaRunner.run(MachinaRunner.java:56) [MachinaCore.jar:?]
    at org.bukkit.craftbukkit.v1_7_R1.scheduler.CraftTask.run(CraftTask.java:67) [craftbukkit.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
    at org.bukkit.craftbukkit.v1_7_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:345) [craftbukkit.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
    at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:614) [craftbukkit.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
    at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:273) [craftbukkit.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
    at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:562) [craftbukkit.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
    at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:469) [craftbukkit.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
    at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [craftbukkit.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
Caused by: java.lang.NullPointerException
    at haveric.stackableItems.listeners.SIPlayerListener.playerPlaceBlock(SIPlayerListener.java:1422) ~[?:?]
    at sun.reflect.GeneratedMethodAccessor222.invoke(Unknown Source) ~[?:?]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.7.0_55]
    at java.lang.reflect.Method.invoke(Method.java:606) ~[?:1.7.0_55]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:318) ~[craftbukkit.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
    ... 17 more