[10:51:26] [Thread-1502/ERROR]: Could not pass event AsyncPlayerPreLoginEvent to ChangeSkin v2.3.1
org.bukkit.event.EventException
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302) ~[PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"8b18730"]
	at co.aikar.timings.TimedEventExecutor.execute(TimedEventExecutor.java:74) ~[PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"8b18730"]
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"8b18730"]
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:501) [PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"8b18730"]
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:483) [PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"8b18730"]
	at net.minecraft.server.v1_8_R3.LoginListener$LoginHandler.fireEvents(LoginListener.java:248) [PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"8b18730"]
	at net.minecraft.server.v1_8_R3.LoginListener$2.run(LoginListener.java:172) [PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"8b18730"]
	at java.lang.Thread.run(Thread.java:745) [?:1.8.0_66]
Caused by: java.lang.NullPointerException
	at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:213) ~[PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"8b18730"]
	at com.google.common.cache.LocalCache.put(LocalCache.java:4144) ~[PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"8b18730"]
	at com.github.games647.changeskin.bukkit.ChangeSkinBukkit.startSession(ChangeSkinBukkit.java:130) ~[?:?]
	at com.github.games647.changeskin.bukkit.listener.AsyncPlayerLoginListener.onPreLogin(AsyncPlayerLoginListener.java:39) ~[?:?]
	at sun.reflect.GeneratedMethodAccessor450.invoke(Unknown Source) ~[?:?]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_66]
	at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_66]
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:300) ~[PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"8b18730"]
	... 7 more