Feb 14, 2011 8:47:23 AM org.bukkit.plugin.SimplePluginManager loadPlugins
SEVERE: Could not load plugins/EssentialsServerlist.jar in plugins: null
org.bukkit.plugin.InvalidPluginException
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:57)
	at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:117)
	at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:82)
	at org.bukkit.craftbukkit.CraftServer.loadPlugins(CraftServer.java:53)
	at net.minecraft.server.MinecraftServer.e(MinecraftServer.java:171)
	at net.minecraft.server.MinecraftServer.c(MinecraftServer.java:158)
	at net.minecraft.server.MinecraftServer.d(MinecraftServer.java:110)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:209)
	at net.minecraft.server.ThreadServerApplication.run(SourceFile:512)
Caused by: java.io.FileNotFoundException: Jar does not contain plugin.yml
	... 9 more