BukkitPluginError

[17:52:48 ERROR]: Could not load 'plugins\tutorial.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.IllegalStateException: JavaPlugin requires org.bukkit.plugin.java.PluginClassLoader
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:131) ~[bukkit-1.7.10-R0.1-20140808.005150-4.jar:?]
	at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:328) ~[bukkit-1.7.10-R0.1-20140808.005150-4.jar:?]
	at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:251) [bukkit-1.7.10-R0.1-20140808.005150-4.jar:?]
	at org.bukkit.craftbukkit.v1_7_R4.CraftServer.loadPlugins(CraftServer.java:364) [craftbukkit-1.7.10-R0.1-20140808.005431-8.jar:git-Bukkit-1.7.9-R0.2-20-g0b2ed13-b3108jnks]
	at org.bukkit.craftbukkit.v1_7_R4.CraftServer.reload(CraftServer.java:837) [craftbukkit-1.7.10-R0.1-20140808.005431-8.jar:git-Bukkit-1.7.9-R0.2-20-g0b2ed13-b3108jnks]
	at org.bukkit.Bukkit.reload(Bukkit.java:303) [bukkit-1.7.10-R0.1-20140808.005150-4.jar:?]
	at org.bukkit.command.defaults.ReloadCommand.execute(ReloadCommand.java:23) [bukkit-1.7.10-R0.1-20140808.005150-4.jar:?]
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:180) [bukkit-1.7.10-R0.1-20140808.005150-4.jar:?]
	at org.bukkit.craftbukkit.v1_7_R4.CraftServer.dispatchCommand(CraftServer.java:740) [craftbukkit-1.7.10-R0.1-20140808.005431-8.jar:git-Bukkit-1.7.9-R0.2-20-g0b2ed13-b3108jnks]
	at org.bukkit.craftbukkit.v1_7_R4.CraftServer.dispatchServerCommand(CraftServer.java:726) [craftbukkit-1.7.10-R0.1-20140808.005431-8.jar:git-Bukkit-1.7.9-R0.2-20-g0b2ed13-b3108jnks]
	at net.minecraft.server.v1_7_R4.DedicatedServer.aB(DedicatedServer.java:294) [craftbukkit-1.7.10-R0.1-20140808.005431-8.jar:git-Bukkit-1.7.9-R0.2-20-g0b2ed13-b3108jnks]
	at net.minecraft.server.v1_7_R4.DedicatedServer.v(DedicatedServer.java:259) [craftbukkit-1.7.10-R0.1-20140808.005431-8.jar:git-Bukkit-1.7.9-R0.2-20-g0b2ed13-b3108jnks]
	at net.minecraft.server.v1_7_R4.MinecraftServer.u(MinecraftServer.java:558) [craftbukkit-1.7.10-R0.1-20140808.005431-8.jar:git-Bukkit-1.7.9-R0.2-20-g0b2ed13-b3108jnks]
	at net.minecraft.server.v1_7_R4.MinecraftServer.run(MinecraftServer.java:469) [craftbukkit-1.7.10-R0.1-20140808.005431-8.jar:git-Bukkit-1.7.9-R0.2-20-g0b2ed13-b3108jnks]
	at net.minecraft.server.v1_7_R4.ThreadServerApplication.run(SourceFile:628) [craftbukkit-1.7.10-R0.1-20140808.005431-8.jar:git-Bukkit-1.7.9-R0.2-20-g0b2ed13-b3108jnks]
Caused by: java.lang.IllegalStateException: JavaPlugin requires org.bukkit.plugin.java.PluginClassLoader
	at org.bukkit.plugin.java.JavaPlugin.<init>(JavaPlugin.java:64) ~[bukkit-1.7.10-R0.1-20140808.005150-4.jar:?]
	at org.readerboy434.TestPlugin.Main.<init>(Main.java:5) ~[bin/:?]
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:1.7.0_45]
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) ~[?:1.7.0_45]
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) ~[?:1.7.0_45]
	at java.lang.reflect.Constructor.newInstance(Unknown Source) ~[?:1.7.0_45]
	at java.lang.Class.newInstance(Unknown Source) ~[?:1.7.0_45]
	at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:52) ~[bukkit-1.7.10-R0.1-20140808.005150-4.jar:?]
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:127) ~[bukkit-1.7.10-R0.1-20140808.005150-4.jar:?]
	... 14 more