Bukkit

[19:49:32] [Server thread/ERROR]: Could not load 'plugins\Statistics.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.NoClassDefFoundError: com/google/gson/Gson
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:135) ~[spigot.jar:git-Spigot-550ebac-7019900]
	at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:329) ~[spigot.jar:git-Spigot-550ebac-7019900]
	at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:251) [spigot.jar:git-Spigot-550ebac-7019900]
	at org.bukkit.craftbukkit.v1_8_R1.CraftServer.loadPlugins(CraftServer.java:291) [spigot.jar:git-Spigot-550ebac-7019900]
	at net.minecraft.server.v1_8_R1.DedicatedServer.init(DedicatedServer.java:152) [spigot.jar:git-Spigot-550ebac-7019900]
	at net.minecraft.server.v1_8_R1.MinecraftServer.run(MinecraftServer.java:505) [spigot.jar:git-Spigot-550ebac-7019900]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_60]
Caused by: java.lang.NoClassDefFoundError: com/google/gson/Gson
	at com.wolvencraft.yasp.Statistics.<init>(Statistics.java:102) ~[?:?]
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:1.8.0_60]
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) ~[?:1.8.0_60]
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) ~[?:1.8.0_60]
	at java.lang.reflect.Constructor.newInstance(Unknown Source) ~[?:1.8.0_60]
	at java.lang.Class.newInstance(Unknown Source) ~[?:1.8.0_60]
	at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:76) ~[spigot.jar:git-Spigot-550ebac-7019900]
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:131) ~[spigot.jar:git-Spigot-550ebac-7019900]
	... 6 more
Caused by: java.lang.ClassNotFoundException: com.google.gson.Gson
	at java.net.URLClassLoader.findClass(Unknown Source) ~[?:1.8.0_60]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:101) ~[spigot.jar:git-Spigot-550ebac-7019900]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:86) ~[spigot.jar:git-Spigot-550ebac-7019900]
	at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_60]
	at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_60]
	at com.wolvencraft.yasp.Statistics.<init>(Statistics.java:102) ~[?:?]
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:1.8.0_60]
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) ~[?:1.8.0_60]
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) ~[?:1.8.0_60]
	at java.lang.reflect.Constructor.newInstance(Unknown Source) ~[?:1.8.0_60]
	at java.lang.Class.newInstance(Unknown Source) ~[?:1.8.0_60]
	at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:76) ~[spigot.jar:git-Spigot-550ebac-7019900]
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:131) ~[spigot.jar:git-Spigot-550ebac-7019900]
	... 6 more