Bukkit

What steps will reproduce the problem?
1. Download HealthBar
2. Drag in to plugins folder
3. Start server

What is the expected output? What do you see instead?
I expect it to load, you know, let everything go fine and dandy, instead I get an error pointing towards Healthbar and PlayerListener

What version of the product are you using?
Latest

Do you have an error log of what happened?
[code] 10:58:45 [SEVERE] Could not load 'plugins/HealthBar.jar' in folder 'plugins' org.bukkit.plugin.InvalidPluginException: java.lang.NoClassDefFoundError: org/bukkit/event/player/PlayerListener at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:149) at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:305) at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:230) at org.bukkit.craftbukkit.CraftServer.loadPlugins(CraftServer.java:213) at org.bukkit.craftbukkit.CraftServer.<init>(CraftServer.java:189) at net.minecraft.server.ServerConfigurationManager.<init>(ServerConfigurationManager.java:53) at net.minecraft.server.MinecraftServer.init(MinecraftServer.java:166) at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:432) at net.minecraft.server.ThreadServerApplication.run(SourceFile:492) Caused by: java.lang.NoClassDefFoundError: org/bukkit/event/player/PlayerListener at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631) at java.lang.ClassLoader.defineClass(ClassLoader.java:615) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141) at java.net.URLClassLoader.defineClass(URLClassLoader.java:283) at java.net.URLClassLoader.access$000(URLClassLoader.java:58) at java.net.URLClassLoader$1.run(URLClassLoader.java:197) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:190) at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:41) at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:29) at java.lang.ClassLoader.loadClass(ClassLoader.java:306) at java.lang.ClassLoader.loadClass(ClassLoader.java:247) at me.plornt.healthbar.HealthBar.<init>(HealthBar.java:28) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:145) ... 8 more Caused by: java.lang.ClassNotFoundException: org.bukkit.event.player.PlayerListener at java.net.URLClassLoader$1.run(URLClassLoader.java:202) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:190) at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:41) at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:29) at java.lang.ClassLoader.loadClass(ClassLoader.java:306) at java.lang.ClassLoader.loadClass(ClassLoader.java:247) ... 27 more [/code]

Please provide any additional information below.
I just redownloaded craftbukkit too :P