Weird Error in Server Logs

I'm not to good with things of this nature, so any and all help will be appreciated. The owner of the server i admin on posted this on our forums today and said that it's happening after a total of 7 people are on the server at one time. Any help would be appreciated as to what it means.

t@s15446493 CB11test]# screen -x​

at net.minecraft.server.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:103)​

at net.minecraft.server.PlayerInstance.<init>(PlayerInstance.java:31)​

at net.minecraft.server.PlayerManager.a(PlayerManager.java:53)​

at net.minecraft.server.PlayerManager.movePlayer(PlayerManager.java:149)​

at net.minecraft.server.ServerConfigurationManager.d(ServerConfigurationManager.java:155)​

at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:387)​

at net.minecraft.server.Packet10Flying.handle(SourceFile:126)​

at net.minecraft.server.NetworkManager.b(NetworkManager.java:226)​

at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:100)​

at net.minecraft.server.NetworkListenThread.a(NetworkListenThread.java:78)​

at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:537)​

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:435)​

at net.minecraft.server.ThreadServerApplication.run(SourceFile:465)​

Caused by: java.lang.reflect.InvocationTargetException​

at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)​

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)​

at java.lang.reflect.Method.invoke(Method.java:601)​

at org.bukkit.plugin.java.JavaPluginLoader$103.execute(JavaPluginLoader.java:1024)​

... 15 more​

Caused by: java.lang.OutOfMemoryError: unable to create new native thread​

at java.lang.Thread.start0(Native Method)​

at java.lang.Thread.start(Thread.java:691)​

at net.minecraft.server.NetworkManager.<init>(NetworkManager.java:69)​

at net.citizensnpcs.resources.npclib.NPCNetworkManager.<init>(NPCNetworkManager.java:14)​

at net.citizensnpcs.resources.npclib.CraftNPC.<init>(CraftNPC.java:21)​

at net.citizensnpcs.resources.npclib.NPCSpawner.spawnNPC(NPCSpawner.java:73)​

at net.citizensnpcs.resources.npclib.NPCManager.register(NPCManager.java:152)​

at net.citizensnpcs.listeners.WorldListen.onChunkLoad(WorldListen.java:54)​

... 19 more​

21:41:54 [SEVERE] java.lang.OutOfMemoryError: unable to create new native thread​

21:41:54 [SEVERE] at java.lang.Thread.start0(Native Method)​

21:41:54 [SEVERE] at java.lang.Thread.start(Thread.java:691)​

21:41:54 [SEVERE] at net.citizensnpcs.utils.Web$LogHandler.publish(Web.java:106)​

21:41:54 [SEVERE] at java.util.logging.Logger.log(Logger.java:522)​

21:41:54 [SEVERE] at java.util.logging.Logger.doLog(Logger.java:543)​

21:41:54 [SEVERE] at java.util.logging.Logger.log(Logger.java:632)​

21:41:54 [SEVERE] at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:473)​

21:41:54 [SEVERE] at net.minecraft.server.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:103)​

21:41:54 [SEVERE] at net.minecraft.server.PlayerInstance.<init>(PlayerInstance.java:31)​

21:41:54 [SEVERE] at net.minecraft.server.PlayerManager.a(PlayerManager.java:53)​

21:41:54 [SEVERE] at net.minecraft.server.PlayerManager.movePlayer(PlayerManager.java:149)​

21:41:54 [SEVERE] at net.minecraft.server.ServerConfigurationManager.d(ServerConfigurationManager.java:155)​

21:41:54 [SEVERE] at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:387)​

21:41:54 [SEVERE] at net.minecraft.server.Packet10Flying.handle(SourceFile:126)​

21:41:54 [SEVERE] at net.minecraft.server.NetworkManager.b(NetworkManager.java:226)​

21:41:54 [SEVERE] at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:100)​

21:41:54 [SEVERE] at net.minecraft.server.NetworkListenThread.a(NetworkListenThread.java:78)​

21:41:54 [SEVERE] at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:537)​

21:41:54 [SEVERE] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:435)​

21:41:54 [SEVERE] at net.minecraft.server.ThreadServerApplication.run(SourceFile:465)​

21:41:54 [SEVERE] Unexpected exception​

java.lang.OutOfMemoryError: unable to create new native thread​

at java.lang.Thread.start0(Native Method)​

at java.lang.Thread.start(Thread.java:691)​

at net.citizensnpcs.utils.Web$LogHandler.publish(Web.java:106)​

at java.util.logging.Logger.log(Logger.java:522)​

at java.util.logging.Logger.doLog(Logger.java:543)​

at java.util.logging.Logger.log(Logger.java:632)​

at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:473)​

at net.minecraft.server.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:103)​

at net.minecraft.server.PlayerInstance.<init>(PlayerInstance.java:31)​

at net.minecraft.server.PlayerManager.a(PlayerManager.java:53)​

at net.minecraft.server.PlayerManager.movePlayer(PlayerManager.java:149)​

at net.minecraft.server.ServerConfigurationManager.d(ServerConfigurationManager.java:155)​

at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:387)​

at net.minecraft.server.Packet10Flying.handle(SourceFile:126)​

at net.minecraft.server.NetworkManager.b(NetworkManager.java:226)​

at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:100)​

at net.minecraft.server.NetworkListenThread.a(NetworkListenThread.java:78)​

at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:537)​

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:435)​

at net.minecraft.server.ThreadServerApplication.run(SourceF​

 

So, i'm not the only admin that this error show..

 

This has been happening to me all day - with no information I have found yet to create this.

 

Found a solution? :/​