[02:57:28] [Server thread/INFO]: [Umbaska] Enabling Umbaska vBETA_1.5.1
[02:57:28] [Server thread/INFO]: [Umbaska] §a[Umbaska] Hooked into metrics! :)
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/INFO]: V1_8_R3
[02:57:28] [Server thread/ERROR]: Error occurred while enabling Umbaska vBETA_1.5.1 (Is it up to date?)
java.lang.NoClassDefFoundError: net/minecraft/server/v1_8_R1/Packet
	at java.lang.Class.getDeclaredConstructors0(Native Method) ~[?:1.8.0_45]
	at java.lang.Class.privateGetDeclaredConstructors(Class.java:2671) ~[?:1.8.0_45]
	at java.lang.Class.getConstructor0(Class.java:3075) ~[?:1.8.0_45]
	at java.lang.Class.getConstructor(Class.java:1825) ~[?:1.8.0_45]
	at ch.njol.skript.lang.SyntaxElementInfo.<init>(SyntaxElementInfo.java:37) ~[?:?]
	at ch.njol.skript.Skript.registerEffect(Skript.java:912) ~[?:?]
	at uk.co.umbaska.Managers.Effects.registerNewEffect(Effects.java:87) ~[?:?]
	at uk.co.umbaska.Managers.Effects.runRegister(Effects.java:290) ~[?:?]
	at uk.co.umbaska.Managers.Register.registerAll(Register.java:38) ~[?:?]
	at uk.co.umbaska.Main.onEnable(Main.java:92) ~[?:?]
	at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:321) ~[spigot-1.8.7.jar:git-Spigot-3ccbe77-a6a57a9]
	at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:340) [spigot-1.8.7.jar:git-Spigot-3ccbe77-a6a57a9]
	at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:405) [spigot-1.8.7.jar:git-Spigot-3ccbe77-a6a57a9]
	at org.bukkit.craftbukkit.v1_8_R3.CraftServer.loadPlugin(CraftServer.java:356) [spigot-1.8.7.jar:git-Spigot-3ccbe77-a6a57a9]
	at org.bukkit.craftbukkit.v1_8_R3.CraftServer.enablePlugins(CraftServer.java:316) [spigot-1.8.7.jar:git-Spigot-3ccbe77-a6a57a9]
	at net.minecraft.server.v1_8_R3.MinecraftServer.s(MinecraftServer.java:418) [spigot-1.8.7.jar:git-Spigot-3ccbe77-a6a57a9]
	at net.minecraft.server.v1_8_R3.MinecraftServer.k(MinecraftServer.java:382) [spigot-1.8.7.jar:git-Spigot-3ccbe77-a6a57a9]
	at net.minecraft.server.v1_8_R3.MinecraftServer.a(MinecraftServer.java:337) [spigot-1.8.7.jar:git-Spigot-3ccbe77-a6a57a9]
	at net.minecraft.server.v1_8_R3.DedicatedServer.init(DedicatedServer.java:256) [spigot-1.8.7.jar:git-Spigot-3ccbe77-a6a57a9]
	at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:528) [spigot-1.8.7.jar:git-Spigot-3ccbe77-a6a57a9]
	at java.lang.Thread.run(Thread.java:745) [?:1.8.0_45]
Caused by: java.lang.ClassNotFoundException: net.minecraft.server.v1_8_R1.Packet
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:91) ~[spigot-1.8.7.jar:git-Spigot-3ccbe77-a6a57a9]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:86) ~[spigot-1.8.7.jar:git-Spigot-3ccbe77-a6a57a9]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0_45]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_45]
	... 21 more