BattleTracker after click on sign

[10:29:51 WARN]: java.lang.ClassNotFoundException: mc.alk.tracker.battlelib.compat.v1_9_R1.SignHandler
[10:29:51 WARN]:        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
[10:29:51 WARN]:        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:101)
[10:29:51 WARN]:        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:86)
[10:29:51 WARN]:        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
[10:29:51 WARN]:        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
[10:29:51 WARN]:        at java.lang.Class.forName0(Native Method)
[10:29:51 WARN]:        at java.lang.Class.forName(Class.java:264)
[10:29:51 WARN]:        at mc.alk.tracker.battlelib.factory.HandlerFactory.getNewInstance(HandlerFactory.java:13)
[10:29:51 WARN]:        at mc.alk.tracker.battlelib.factory.SignHandlerFactory.getNewInstance(SignHandlerFactory.java:10)
[10:29:51 WARN]:        at mc.alk.tracker.battlelib.SignUtil.<clinit>(SignUtil.java:11)
[10:29:51 WARN]:        at mc.alk.tracker.controllers.SignController.updateSign(SignController.java:385)
[10:29:51 WARN]:        at mc.alk.tracker.controllers.SignController.updateTopSign(SignController.java:365)
[10:29:51 WARN]:        at mc.alk.tracker.controllers.SignController.clickedSign(SignController.java:353)
[10:29:51 WARN]:        at mc.alk.tracker.listeners.SignListener.onPlayerInteract(SignListener.java:59)
[10:29:51 WARN]:        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[10:29:51 WARN]:        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
[10:29:51 WARN]:        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[10:29:51 WARN]:        at java.lang.reflect.Method.invoke(Method.java:498)
[10:29:51 WARN]:        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306)
[10:29:51 WARN]:        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
[10:29:51 WARN]:        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502)
[10:29:51 WARN]:        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487)
[10:29:51 WARN]:        at org.bukkit.craftbukkit.v1_9_R1.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:231)
[10:29:51 WARN]:        at org.bukkit.craftbukkit.v1_9_R1.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:198)
[10:29:51 WARN]:        at net.minecraft.server.v1_9_R1.PlayerInteractManager.a(PlayerInteractManager.java:110)
[10:29:51 WARN]:        at net.minecraft.server.v1_9_R1.PlayerConnection.a(PlayerConnection.java:832)
[10:29:51 WARN]:        at net.minecraft.server.v1_9_R1.PacketPlayInBlockDig.a(SourceFile:40)
[10:29:51 WARN]:        at net.minecraft.server.v1_9_R1.PacketPlayInBlockDig.a(SourceFile:10)
[10:29:51 WARN]:        at net.minecraft.server.v1_9_R1.PlayerConnectionUtils$1.run(SourceFile:13)
[10:29:51 WARN]:        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
[10:29:51 WARN]:        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
[10:29:51 WARN]:        at net.minecraft.server.v1_9_R1.SystemUtils.a(SourceFile:45)
[10:29:51 WARN]:        at net.minecraft.server.v1_9_R1.MinecraftServer.D(MinecraftServer.java:721)
[10:29:51 WARN]:        at net.minecraft.server.v1_9_R1.DedicatedServer.D(DedicatedServer.java:400)
[10:29:51 WARN]:        at net.minecraft.server.v1_9_R1.MinecraftServer.C(MinecraftServer.java:660)
[10:29:51 WARN]:        at net.minecraft.server.v1_9_R1.MinecraftServer.run(MinecraftServer.java:559)
[10:29:51 WARN]:        at java.lang.Thread.run(Thread.java:745)