In the console, i see the Error that is included below. Is it a general bukkit thing or is it a plugin problem? Spoiler (Move your mouse to the spoiler area to reveal the content) Show Spoiler Hide Spoiler 19:30:38 [INFO] Caught java.lang.ClassCastException exception in EntityPotionColorPacketAdapter#onPacketSending 19:30:38 [INFO] Message: org.bukkit.craftbukkit.v1_5_R2.inventory.CraftItemStack cannot be cast to java.lang.Integer 19:30:38 [INFO] Stack Trace: 19:30:38 [SEVERE] java.lang.ClassCastException: org.bukkit.craftbukkit.v1_5_R2.inventory.CraftItemStack cannot be cast to java.lang.Integer 19:30:38 [SEVERE] at com.massivecraft.mcore.integration.protocollib.EntityPotionColorPacketAdapter.onPacketSending(EntityPotionColorPacketAdapter.java:65) 19:30:38 [SEVERE] at com.comphenix.protocol.injector.SortedPacketListenerList.invokePacketSending(SortedPacketListenerList.java:70) 19:30:38 [SEVERE] at com.comphenix.protocol.injector.PacketFilterManager.handlePacket(PacketFilterManager.java:440) 19:30:38 [SEVERE] at com.comphenix.protocol.injector.PacketFilterManager.invokePacketSending(PacketFilterManager.java:420) 19:30:38 [SEVERE] at com.comphenix.protocol.injector.player.PlayerInjector.handlePacketSending(PlayerInjector.java:548) 19:30:38 [SEVERE] at com.comphenix.protocol.injector.player.NetworkServerInjector$1.intercept(NetworkServerInjector.java:148) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.PlayerConnection$$EnhancerByCGLIB$$25b3e7ba.sendPacket(<generated>) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.EntityTrackerEntry.updatePlayer(EntityTrackerEntry.java:311) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.EntityTrackerEntry.scanPlayers(EntityTrackerEntry.java:372) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.EntityTracker.addEntity(EntityTracker.java:105) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.EntityTracker.track(EntityTracker.java:55) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.WorldManager.a(WorldManager.java:18) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.World.a(World.java:959) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.WorldServer.a(WorldServer.java:778) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.World.addEntity(World.java:952) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.World.addEntity(World.java:897) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.ItemFireworks.interactWith(SourceFile:43) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.ItemStack.placeItem(ItemStack.java:79) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.PlayerInteractManager.interact(PlayerInteractManager.java:386) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.PlayerConnection.a(PlayerConnection.java:632) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.Packet15Place.handle(SourceFile:58) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.NetworkManager.b(NetworkManager.java:292) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.PlayerConnection.d(PlayerConnection.java:110) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.ServerConnection.b(SourceFile:35) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.DedicatedServerConnection.b(SourceFile:30) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.MinecraftServer.r(MinecraftServer.java:578) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.DedicatedServer.r(DedicatedServer.java:225) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.MinecraftServer.q(MinecraftServer.java:474) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.MinecraftServer.run(MinecraftServer.java:407) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.ThreadServerApplication.run(SourceFile:573) 19:30:38 [INFO] Caught java.lang.ClassCastException exception in EntityPotionColorPacketAdapter#onPacketSending 19:30:38 [INFO] Message: org.bukkit.craftbukkit.v1_5_R2.inventory.CraftItemStack cannot be cast to java.lang.Integer 19:30:38 [INFO] Stack Trace: 19:30:38 [SEVERE] java.lang.ClassCastException: org.bukkit.craftbukkit.v1_5_R2.inventory.CraftItemStack cannot be cast to java.lang.Integer 19:30:38 [SEVERE] at com.massivecraft.mcore.integration.protocollib.EntityPotionColorPacketAdapter.onPacketSending(EntityPotionColorPacketAdapter.java:65) 19:30:38 [SEVERE] at com.comphenix.protocol.injector.SortedPacketListenerList.invokePacketSending(SortedPacketListenerList.java:70) 19:30:38 [SEVERE] at com.comphenix.protocol.injector.PacketFilterManager.handlePacket(PacketFilterManager.java:440) 19:30:38 [SEVERE] at com.comphenix.protocol.injector.PacketFilterManager.invokePacketSending(PacketFilterManager.java:420) 19:30:38 [SEVERE] at com.comphenix.protocol.injector.player.PlayerInjector.handlePacketSending(PlayerInjector.java:548) 19:30:38 [SEVERE] at com.comphenix.protocol.injector.player.NetworkServerInjector$1.intercept(NetworkServerInjector.java:148) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.PlayerConnection$$EnhancerByCGLIB$$25b3e7ba.sendPacket(<generated>) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.EntityTrackerEntry.updatePlayer(EntityTrackerEntry.java:311) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.EntityTrackerEntry.scanPlayers(EntityTrackerEntry.java:372) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.EntityTracker.addEntity(EntityTracker.java:105) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.EntityTracker.track(EntityTracker.java:55) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.WorldManager.a(WorldManager.java:18) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.World.a(World.java:959) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.WorldServer.a(WorldServer.java:778) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.World.addEntity(World.java:952) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.World.addEntity(World.java:897) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.ItemFireworks.interactWith(SourceFile:43) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.ItemStack.placeItem(ItemStack.java:79) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.PlayerInteractManager.interact(PlayerInteractManager.java:386) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.PlayerConnection.a(PlayerConnection.java:632) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.Packet15Place.handle(SourceFile:58) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.NetworkManager.b(NetworkManager.java:292) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.PlayerConnection.d(PlayerConnection.java:110) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.ServerConnection.b(SourceFile:35) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.DedicatedServerConnection.b(SourceFile:30) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.MinecraftServer.r(MinecraftServer.java:578) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.DedicatedServer.r(DedicatedServer.java:225) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.MinecraftServer.q(MinecraftServer.java:474) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.MinecraftServer.run(MinecraftServer.java:407) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.ThreadServerApplication.run(SourceFile:573) 19:30:38 [INFO] Caught java.lang.ClassCastException exception in EntityPotionColorPacketAdapter#onPacketSending 19:30:38 [INFO] Message: org.bukkit.craftbukkit.v1_5_R2.inventory.CraftItemStack cannot be cast to java.lang.Integer 19:30:38 [INFO] Stack Trace: 19:30:38 [SEVERE] java.lang.ClassCastException: org.bukkit.craftbukkit.v1_5_R2.inventory.CraftItemStack cannot be cast to java.lang.Integer 19:30:38 [SEVERE] at com.massivecraft.mcore.integration.protocollib.EntityPotionColorPacketAdapter.onPacketSending(EntityPotionColorPacketAdapter.java:65) 19:30:38 [SEVERE] at com.comphenix.protocol.injector.SortedPacketListenerList.invokePacketSending(SortedPacketListenerList.java:70) 19:30:38 [SEVERE] at com.comphenix.protocol.injector.PacketFilterManager.handlePacket(PacketFilterManager.java:440) 19:30:38 [SEVERE] at com.comphenix.protocol.injector.PacketFilterManager.invokePacketSending(PacketFilterManager.java:420) 19:30:38 [SEVERE] at com.comphenix.protocol.injector.player.PlayerInjector.handlePacketSending(PlayerInjector.java:548) 19:30:38 [SEVERE] at com.comphenix.protocol.injector.player.NetworkServerInjector$1.intercept(NetworkServerInjector.java:148) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.PlayerConnection$$EnhancerByCGLIB$$25b3e7ba.sendPacket(<generated>) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.EntityTrackerEntry.broadcast(EntityTrackerEntry.java:260) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.EntityTrackerEntry.broadcastIncludingSelf(EntityTrackerEntry.java:265) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.EntityTrackerEntry.track(EntityTrackerEntry.java:177) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.EntityTracker.updatePlayers(EntityTracker.java:153) 19:30:38 [SEVERE] at net.minecraft.server.v1_5_R2.MinecraftServer.r(MinecraftServer.java:569) 19:30:39 [SEVERE] at net.minecraft.server.v1_5_R2.DedicatedServer.r(DedicatedServer.java:225) 19:30:39 [SEVERE] at net.minecraft.server.v1_5_R2.MinecraftServer.q(MinecraftServer.java:474) 19:30:39 [SEVERE] at net.minecraft.server.v1_5_R2.MinecraftServer.run(MinecraftServer.java:407) 19:30:39 [SEVERE] at net.minecraft.server.v1_5_R2.ThreadServerApplication.run(SourceFile:573) 19:30:39 [INFO] Caught java.lang.ClassCastException exception in EntityPotionColorPacketAdapter#onPacketSending 19:30:39 [INFO] Message: org.bukkit.craftbukkit.v1_5_R2.inventory.CraftItemStack cannot be cast to java.lang.Integer 19:30:39 [INFO] Stack Trace: 19:30:39 [SEVERE] java.lang.ClassCastException: org.bukkit.craftbukkit.v1_5_R2.inventory.CraftItemStack cannot be cast to java.lang.Integer 19:30:39 [SEVERE] at com.massivecraft.mcore.integration.protocollib.EntityPotionColorPacketAdapter.onPacketSending(EntityPotionColorPacketAdapter.java:65) 19:30:39 [SEVERE] at com.comphenix.protocol.injector.SortedPacketListenerList.invokePacketSending(SortedPacketListenerList.java:70) 19:30:39 [SEVERE] at com.comphenix.protocol.injector.PacketFilterManager.handlePacket(PacketFilterManager.java:440) 19:30:39 [SEVERE] at com.comphenix.protocol.injector.PacketFilterManager.invokePacketSending(PacketFilterManager.java:420) 19:30:39 [SEVERE] at com.comphenix.protocol.injector.player.PlayerInjector.handlePacketSending(PlayerInjector.java:548) 19:30:39 [SEVERE] at com.comphenix.protocol.injector.player.NetworkServerInjector$1.intercept(NetworkServerInjector.java:148) 19:30:39 [SEVERE] at net.minecraft.server.v1_5_R2.PlayerConnection$$EnhancerByCGLIB$$25b3e7ba.sendPacket(<generated>) 19:30:39 [SEVERE] at net.minecraft.server.v1_5_R2.EntityTrackerEntry.broadcast(EntityTrackerEntry.java:260) 19:30:39 [SEVERE] at net.minecraft.server.v1_5_R2.EntityTrackerEntry.broadcastIncludingSelf(EntityTrackerEntry.java:265) 19:30:39 [SEVERE] at net.minecraft.server.v1_5_R2.EntityTrackerEntry.track(EntityTrackerEntry.java:177) 19:30:39 [SEVERE] at net.minecraft.server.v1_5_R2.EntityTracker.updatePlayers(EntityTracker.java:153) 19:30:39 [SEVERE] at net.minecraft.server.v1_5_R2.MinecraftServer.r(MinecraftServer.java:569) 19:30:39 [SEVERE] at net.minecraft.server.v1_5_R2.DedicatedServer.r(DedicatedServer.java:225) 19:30:39 [SEVERE] at net.minecraft.server.v1_5_R2.MinecraftServer.q(MinecraftServer.java:474) 19:30:39 [SEVERE] at net.minecraft.server.v1_5_R2.MinecraftServer.run(MinecraftServer.java:407) 19:30:39 [SEVERE] at net.minecraft.server.v1_5_R2.ThreadServerApplication.run(SourceFile:573)