When someone logs on to my server this is the message I get: Code: 20:38:58 [SEVERE] java.lang.ClassFormatError: Incompatible magic value 1 in class file /DS_Store 20:38:58 [SEVERE]at java.lang.ClassLoader.defineClass1(Native Method) 20:38:58 [SEVERE]at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631) 20:38:58 [SEVERE]at java.lang.ClassLoader.defineClass(ClassLoader.java:615) 20:38:58 [SEVERE]at java.lang.ClassLoader.defineClass(ClassLoader.java:465) 20:38:58 [SEVERE]at com.sk89q.worldedit.bukkit.BukkitWorld$NmsBlockClassLoader.loadClass(BukkitWorld.java:228) 20:38:58 [SEVERE]at com.sk89q.worldedit.bukkit.BukkitWorld.<init>(BukkitWorld.java:146) 20:38:58 [SEVERE]at com.sk89q.worldedit.bukkit.BukkitUtil.getLocalWorld(BukkitUtil.java:50) 20:38:58 [SEVERE]at com.sk89q.worldedit.bukkit.BukkitPlayer.getWorld(BukkitPlayer.java:132) 20:38:58 [SEVERE]at com.worldcretornica.plotme.PlotWorldEdit.setMask(PlotWorldEdit.java:42) 20:38:58 [SEVERE]at com.worldcretornica.plotme.PlotWorldEdit.setMask(PlotWorldEdit.java:18) 20:38:58 [SEVERE]at com.worldcretornica.plotme.listener.PlotWorldEditListener.onPlayerJoin(PlotWorldEditListener.java:66) 20:38:58 [SEVERE]at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 20:38:58 [SEVERE]at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 20:38:58 [SEVERE]at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 20:38:58 [SEVERE]at java.lang.reflect.Method.invoke(Method.java:597) 20:38:58 [SEVERE]at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425) 20:38:58 [SEVERE]at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) 20:38:58 [SEVERE]at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:477) 20:38:58 [SEVERE]at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:462) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.PlayerList.c(PlayerList.java:159) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.PlayerList.a(PlayerList.java:98) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.PendingConnection.d(PendingConnection.java:130) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.PendingConnection.c(PendingConnection.java:45) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.DedicatedServerConnectionThread.a(DedicatedServerConnectionThread.java:44) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.DedicatedServerConnection.b(SourceFile:29) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.MinecraftServer.r(MinecraftServer.java:598) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.DedicatedServer.r(DedicatedServer.java:224) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.MinecraftServer.q(MinecraftServer.java:494) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.MinecraftServer.run(MinecraftServer.java:427) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.ThreadServerApplication.run(SourceFile:849) 20:38:58 [SEVERE] java.lang.UnsupportedClassVersionError: MCPCPlusXNmsBlock_147 : Unsupported major.minor version 51.0 20:38:58 [SEVERE]at java.lang.ClassLoader.defineClass1(Native Method) 20:38:58 [SEVERE]at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631) 20:38:58 [SEVERE]at java.lang.ClassLoader.defineClass(ClassLoader.java:615) 20:38:58 [SEVERE]at java.lang.ClassLoader.defineClass(ClassLoader.java:465) 20:38:58 [SEVERE]at com.sk89q.worldedit.bukkit.BukkitWorld$NmsBlockClassLoader.loadClass(BukkitWorld.java:228) 20:38:58 [SEVERE]at com.sk89q.worldedit.bukkit.BukkitWorld.<init>(BukkitWorld.java:146) 20:38:58 [SEVERE]at com.sk89q.worldedit.bukkit.BukkitUtil.getLocalWorld(BukkitUtil.java:50) 20:38:58 [SEVERE]at com.sk89q.worldedit.bukkit.BukkitPlayer.getWorld(BukkitPlayer.java:132) 20:38:58 [SEVERE]at com.worldcretornica.plotme.PlotWorldEdit.setMask(PlotWorldEdit.java:42) 20:38:58 [SEVERE]at com.worldcretornica.plotme.PlotWorldEdit.setMask(PlotWorldEdit.java:18) 20:38:58 [SEVERE]at com.worldcretornica.plotme.listener.PlotWorldEditListener.onPlayerJoin(PlotWorldEditListener.java:66) 20:38:58 [SEVERE]at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 20:38:58 [SEVERE]at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 20:38:58 [SEVERE]at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 20:38:58 [SEVERE]at java.lang.reflect.Method.invoke(Method.java:597) 20:38:58 [SEVERE]at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425) 20:38:58 [SEVERE]at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) 20:38:58 [SEVERE]at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:477) 20:38:58 [SEVERE]at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:462) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.PlayerList.c(PlayerList.java:159) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.PlayerList.a(PlayerList.java:98) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.PendingConnection.d(PendingConnection.java:130) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.PendingConnection.c(PendingConnection.java:45) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.DedicatedServerConnectionThread.a(DedicatedServerConnectionThread.java:44) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.DedicatedServerConnection.b(SourceFile:29) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.MinecraftServer.r(MinecraftServer.java:598) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.DedicatedServer.r(DedicatedServer.java:224) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.MinecraftServer.q(MinecraftServer.java:494) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.MinecraftServer.run(MinecraftServer.java:427) 20:38:58 [SEVERE]at net.minecraft.server.v1_4_R1.ThreadServerApplication.run(SourceFile:849) Yes, I have the Bukkit Recommended Build and the newest version of Worldedit, Worldguard and PlotMe. I have the latest version of Java for Mac 1.8