Ht error

[16:10:59] [Server thread/ERROR]: Could not load 'plugins\ht.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.ClassCastException: class se.albin900.httptools.Httptools
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:184) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.2-1-gbafd450-b2975jnks]
	at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:308) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.2-1-gbafd450-b2975jnks]
	at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:231) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-1-gbafd450-b2975jnks]
	at org.bukkit.craftbukkit.v1_7_R1.CraftServer.loadPlugins(CraftServer.java:255) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-1-gbafd450-b2975jnks]
	at org.bukkit.craftbukkit.v1_7_R1.CraftServer.<init>(CraftServer.java:233) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-1-gbafd450-b2975jnks]
	at net.minecraft.server.v1_7_R1.PlayerList.<init>(PlayerList.java:63) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-1-gbafd450-b2975jnks]
	at net.minecraft.server.v1_7_R1.DedicatedPlayerList.<init>(SourceFile:14) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-1-gbafd450-b2975jnks]
	at net.minecraft.server.v1_7_R1.DedicatedServer.init(DedicatedServer.java:126) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-1-gbafd450-b2975jnks]
	at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:424) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-1-gbafd450-b2975jnks]
	at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-1-gbafd450-b2975jnks]
Caused by: java.lang.ClassCastException: class se.albin900.httptools.Httptools
	at java.lang.Class.asSubclass(Unknown Source) ~[?:1.7.0_15]
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:174) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.2-1-gbafd450-b2975jnks]
	... 9 more