[23:16:22 ERROR]: Could not pass event PlayerJoinEvent to BookRules v2.1.1 org.bukkit.event.EventException at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302) ~[spigot-1625.jar:git-Spigot-1625] at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot-1625.jar:git-Spigot-1625] at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot-1625.jar:git-Spigot-1625] at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [spigot-1625.jar:git-Spigot-1625] at net.minecraft.server.v1_7_R4.PlayerList.c(PlayerList.java:265) [spigot-1625.jar:git-Spigot-1625] at net.minecraft.server.v1_7_R4.PlayerList.a(PlayerList.java:152) [spigot-1625.jar:git-Spigot-1625] at net.minecraft.server.v1_7_R4.LoginListener.c(LoginListener.java:105) [spigot-1625.jar:git-Spigot-1625] at net.minecraft.server.v1_7_R4.LoginListener.a(LoginListener.java:43) [spigot-1625.jar:git-Spigot-1625] at net.minecraft.server.v1_7_R4.NetworkManager.a(NetworkManager.java:187) [spigot-1625.jar:git-Spigot-1625] at net.minecraft.server.v1_7_R4.ServerConnection.c(ServerConnection.java:81) [spigot-1625.jar:git-Spigot-1625] at net.minecraft.server.v1_7_R4.MinecraftServer.v(MinecraftServer.java:734) [spigot-1625.jar:git-Spigot-1625] at net.minecraft.server.v1_7_R4.DedicatedServer.v(DedicatedServer.java:289) [spigot-1625.jar:git-Spigot-1625] at net.minecraft.server.v1_7_R4.MinecraftServer.u(MinecraftServer.java:584) [spigot-1625.jar:git-Spigot-1625] at net.minecraft.server.v1_7_R4.MinecraftServer.run(MinecraftServer.java:490) [spigot-1625.jar:git-Spigot-1625] at net.minecraft.server.v1_7_R4.ThreadServerApplication.run(SourceFile:628) [spigot-1625.jar:git-Spigot-1625] Caused by: java.lang.NullPointerException at com.mstiles92.plugins.bookrules.listeners.PlayerListener.onPlayerJoin(PlayerListener.java:52) ~[?:?] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0_21] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) ~[?:1.7.0_21] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.7.0_21] at java.lang.reflect.Method.invoke(Method.java:601) ~[?:1.7.0_21] at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:298) ~[spigot-1625.jar:git-Spigot-1625] ... 14 more