Server always crashes when 20+ players are on....

Hi, my server ALWAYS crashes when 20+ players are on for about 5-10 min...
Here's the crash report:
https://dl.dropboxusercontent.com/u/66403069/Neuer Ordner/crash.txt

Thx for help.

 

Pastebin your full startup log.

 

Evilshallwin https://dl.dropboxusercontent.com/u/66403069/Neuer Ordner/server.log
Crash report at the bottom

 

Metal Julien
How much plugins do you have on your server?

 

InspectorFacepalm 36

 

I suggest you look at your memory usage at the time of 19 players VS 20+. I can almost bet that you run out of ram. what does your server.log states something of "read time out". Unfortunally, the network I am on does not allow me to view pastie or pastbin. Both sites are blocked. (government internet)

EDIT:
this is my observation from your server.log...

2013-05-28 15:26:25 [SEVERE] [DragonTravel] Messages file is outdated!
2013-05-28 15:26:25 [SEVERE] [DragonTravel] Delete existing Messages-File and generate a new one
Delete your message file and generate a new one.

2013-05-28 15:26:29 [WARNING] [NoCheatPlus] Could not set up native access for your specific Minecraft + server-mod version.
2013-05-28 15:26:29 [WARNING] [NoCheatPlus] API-only MCAccess: Some features will likely not function properly, performance might suffer.
2013-05-28 15:26:29 [WARNING] [NoCheatPlus] Check for updates at BukkitDev: http://dev.bukkit.org/server-mods/nocheatplus/
2013-05-28 15:26:29 [WARNING] [NoCheatPlus] Development builds: http://ci.ecocitycraft.com/job/NoCheatPlus/
Is NCP updated?

2013-05-28 15:26:30 [SEVERE] Error occurred while enabling VoxelSniper v5.168.5-SNAPSHOT-jnks201 (Is it up to date?)
java.lang.NoClassDefFoundError: net/minecraft/server/v1_5_R1/EntityLiving
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Unknown Source)
at java.lang.Class.getConstructor0(Unknown Source)
at java.lang.Class.getConstructor(Unknown Source)
at com.thevoxelbox.voxelsniper.SniperBrushes.getBrush(SniperBrushes.java:240)
at com.thevoxelbox.voxelsniper.SniperBrushes.getSniperBrushes(SniperBrushes.java:180)
at com.thevoxelbox.voxelsniper.MetricsManager.start(MetricsManager.java:138)
at com.thevoxelbox.voxelsniper.VoxelSniper.onEnable(VoxelSniper.java:314)
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:457)
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:381)
at org.bukkit.craftbukkit.v1_5_R3.CraftServer.loadPlugin(CraftServer.java:282)
at org.bukkit.craftbukkit.v1_5_R3.CraftServer.enablePlugins(CraftServer.java:264)
at net.minecraft.server.v1_5_R3.MinecraftServer.j(MinecraftServer.java:304)
at net.minecraft.server.v1_5_R3.MinecraftServer.e(MinecraftServer.java:283)
at net.minecraft.server.v1_5_R3.MinecraftServer.a(MinecraftServer.java:243)
at net.minecraft.server.v1_5_R3.DedicatedServer.init(DedicatedServer.java:151)
at net.minecraft.server.v1_5_R3.MinecraftServer.run(MinecraftServer.java:382)
at net.minecraft.server.v1_5_R3.ThreadServerApplication.run(SourceFile:573)
Caused by: java.lang.ClassNotFoundException: net.minecraft.server.v1_5_R1.EntityLiving
at org.bukkit.plugin.java.PluginClassLoader.findClass0(PluginClassLoader.java:70)
at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:53)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 19 more
Update Voxel Sniper

2013-05-28 15:26:31 [SEVERE] Error occurred while enabling Multiverse-Core v2.5-b665 (Is it up to date?)
java.lang.NullPointerException
at com.onarandombox.MultiverseCore.MVWorld.<init>(MVWorld.java:64)
at com.onarandombox.MultiverseCore.MVWorld.<init>(MVWorld.java:56)
at com.onarandombox.MultiverseCore.utils.WorldManager.doLoad(WorldManager.java:415)
at com.onarandombox.MultiverseCore.utils.WorldManager.doLoad(WorldManager.java:390)
at com.onarandombox.MultiverseCore.utils.WorldManager.doLoad(WorldManager.java:365)
at com.onarandombox.MultiverseCore.utils.WorldManager.loadWorlds(WorldManager.java:664)
at com.onarandombox.MultiverseCore.MultiverseCore.onEnable(MultiverseCore.java:300)
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:457)
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:381)
at org.bukkit.craftbukkit.v1_5_R3.CraftServer.loadPlugin(CraftServer.java:282)
at org.bukkit.craftbukkit.v1_5_R3.CraftServer.enablePlugins(CraftServer.java:264)
at net.minecraft.server.v1_5_R3.MinecraftServer.j(MinecraftServer.java:304)
at net.minecraft.server.v1_5_R3.MinecraftServer.e(MinecraftServer.java:283)
at net.minecraft.server.v1_5_R3.MinecraftServer.a(MinecraftServer.java:243)
at net.minecraft.server.v1_5_R3.DedicatedServer.init(DedicatedServer.java:151)
at net.minecraft.server.v1_5_R3.MinecraftServer.run(MinecraftServer.java:382)
at net.minecraft.server.v1_5_R3.ThreadServerApplication.run(SourceFile:573)
Update Multiverse-Core

2013-05-28 15:26:45 [SEVERE] Error occurred while enabling SilkSpawners v3.2.1 (Is it up to date?)
java.lang.NoClassDefFoundError: net/minecraft/server/v1_5_R2/EntityTypes
at de.dustplanet.util.SilkUtil.scanEntityMap(SilkUtil.java:312)
at de.dustplanet.silkspawners.SilkSpawners.loadConfigs(SilkSpawners.java:232)
at de.dustplanet.silkspawners.SilkSpawners.onEnable(SilkSpawners.java:71)
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:457)
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:381)
at org.bukkit.craftbukkit.v1_5_R3.CraftServer.loadPlugin(CraftServer.java:282)
at org.bukkit.craftbukkit.v1_5_R3.CraftServer.enablePlugins(CraftServer.java:264)
at net.minecraft.server.v1_5_R3.MinecraftServer.j(MinecraftServer.java:304)
at net.minecraft.server.v1_5_R3.MinecraftServer.e(MinecraftServer.java:283)
at net.minecraft.server.v1_5_R3.MinecraftServer.a(MinecraftServer.java:243)
at net.minecraft.server.v1_5_R3.DedicatedServer.init(DedicatedServer.java:151)
at net.minecraft.server.v1_5_R3.MinecraftServer.run(MinecraftServer.java:382)
at net.minecraft.server.v1_5_R3.ThreadServerApplication.run(SourceFile:573)
Caused by: java.lang.ClassNotFoundException: net.minecraft.server.v1_5_R2.EntityTypes
at org.bukkit.plugin.java.PluginClassLoader.findClass0(PluginClassLoader.java:70)
at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:53)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 14 more
Update Silk Spawners

2013-05-28 15:26:45 [SEVERE] java.io.EOFException
2013-05-28 15:26:45 [SEVERE] at java.ibjectInputStream$BlockDataInputStream.peekByte(Unknown Source)
2013-05-28 15:26:45 [SEVERE] at java.ibjectInputStream.readObject0(Unknown Source)
2013-05-28 15:26:45 [SEVERE] at java.ibjectInputStream.defaultReadFields(Unknown Source)
2013-05-28 15:26:45 [SEVERE] at java.ibjectInputStream.readSerialData(Unknown Source)
2013-05-28 15:26:45 [SEVERE] at java.ibjectInputStream.readOrdinaryObject(Unknown Source)
2013-05-28 15:26:45 [SEVERE] at java.ibjectInputStream.readObject0(Unknown Source)
2013-05-28 15:26:45 [SEVERE] at java.ibjectInputStream.readObject(Unknown Source)
2013-05-28 15:26:45 [SEVERE] at com.github.thebiologist13.FileManager.loadEntity(FileManager.java:192)
2013-05-28 15:26:45 [SEVERE] at com.github.thebiologist13.FileManager.loadEntities(FileManager.java:168)
2013-05-28 15:26:45 [SEVERE] at com.github.thebiologist13.CustomSpawners.onEnable(CustomSpawners.java:837)
2013-05-28 15:26:45 [SEVERE] at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)
2013-05-28 15:26:45 [SEVERE] at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:457)
2013-05-28 15:26:45 [SEVERE] at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:381)
2013-05-28 15:26:45 [SEVERE] at org.bukkit.craftbukkit.v1_5_R3.CraftServer.loadPlugin(CraftServer.java:282)
2013-05-28 15:26:45 [SEVERE] at org.bukkit.craftbukkit.v1_5_R3.CraftServer.enablePlugins(CraftServer.java:264)
2013-05-28 15:26:45 [SEVERE] at net.minecraft.server.v1_5_R3.MinecraftServer.j(MinecraftServer.java:304)
2013-05-28 15:26:45 [SEVERE] at net.minecraft.server.v1_5_R3.MinecraftServer.e(MinecraftServer.java:283)
2013-05-28 15:26:45 [SEVERE] at net.minecraft.server.v1_5_R3.MinecraftServer.a(MinecraftServer.java:243)
2013-05-28 15:26:45 [SEVERE] at net.minecraft.server.v1_5_R3.DedicatedServer.init(DedicatedServer.java:151)
2013-05-28 15:26:45 [SEVERE] at net.minecraft.server.v1_5_R3.MinecraftServer.run(MinecraftServer.java:382)
2013-05-28 15:26:45 [SEVERE] at net.minecraft.server.v1_5_R3.ThreadServerApplication.run(SourceFile:573)
2013-05-28 15:26:45 [SEVERE] Failed to load entity fromplugins\CustomSpawners\Entities\0.dat!
2013-05-28 15:26:45 [INFO] Failed to load from plugins\CustomSpawners\Entities\0.dat
Custom spawners has an issue here...

2013-05-28 15:27:02 [WARNING] [RecipeManager] Task #14 for RecipeManager v1.26b.ryantheleach.1.5.1 generated an exception
java.lang.NoClassDefFoundError: net/minecraft/server/v1_5_R2/Item
at digi.recipeManager.RecipeManager.loadSettings(RecipeManager.java:278)
at digi.recipeManager.RecipeManager$1.run(RecipeManager.java:82)
at org.bukkit.craftbukkit.v1_5_R3.scheduler.CraftTask.run(CraftTask.java:53)
at org.bukkit.craftbukkit.v1_5_R3.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:345)
at net.minecraft.server.v1_5_R3.MinecraftServer.r(MinecraftServer.java:513)
at net.minecraft.server.v1_5_R3.DedicatedServer.r(DedicatedServer.java:226)
at net.minecraft.server.v1_5_R3.MinecraftServer.q(MinecraftServer.java:477)
at net.minecraft.server.v1_5_R3.MinecraftServer.run(MinecraftServer.java:410)
at net.minecraft.server.v1_5_R3.ThreadServerApplication.run(SourceFile:573)
Caused by: java.lang.ClassNotFoundException: net.minecraft.server.v1_5_R2.Item
at org.bukkit.plugin.java.PluginClassLoader.findClass0(PluginClassLoader.java:70)
at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:53)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 9 more
Recipe Manager also has an issue...

2013-05-28 15:27:02 [WARNING] [RecipeManager] Task #14 for RecipeManager v1.26b.ryantheleach.1.5.1 generated an exception
java.lang.NoClassDefFoundError: net/minecraft/server/v1_5_R2/Item
at digi.recipeManager.RecipeManager.loadSettings(RecipeManager.java:278)
at digi.recipeManager.RecipeManager$1.run(RecipeManager.java:82)
at org.bukkit.craftbukkit.v1_5_R3.scheduler.CraftTask.run(CraftTask.java:53)
at org.bukkit.craftbukkit.v1_5_R3.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:345)
at net.minecraft.server.v1_5_R3.MinecraftServer.r(MinecraftServer.java:513)
at net.minecraft.server.v1_5_R3.DedicatedServer.r(DedicatedServer.java:226)
at net.minecraft.server.v1_5_R3.MinecraftServer.q(MinecraftServer.java:477)
at net.minecraft.server.v1_5_R3.MinecraftServer.run(MinecraftServer.java:410)
at net.minecraft.server.v1_5_R3.ThreadServerApplication.run(SourceFile:573)
Caused by: java.lang.ClassNotFoundException: net.minecraft.server.v1_5_R2.Item
at org.bukkit.plugin.java.PluginClassLoader.findClass0(PluginClassLoader.java:70)
at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:53)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 9 more
Are we missing a world???

2013-06-03 17:24:11 [SEVERE] java.util.ConcurrentModificationException
2013-06-03 17:24:11 [SEVERE] at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
2013-06-03 17:24:11 [SEVERE] at java.util.HashMap$KeyIterator.next(Unknown Source)
2013-06-03 17:24:11 [SEVERE] at net.minecraft.server.v1_5_R3.EntityTracker.updatePlayers(EntityTracker.java:151)
2013-06-03 17:24:11 [SEVERE] at net.minecraft.server.v1_5_R3.MinecraftServer.r(MinecraftServer.java:572)
2013-06-03 17:24:11 [SEVERE] at net.minecraft.server.v1_5_R3.DedicatedServer.r(DedicatedServer.java:226)
2013-06-03 17:24:11 [SEVERE] at net.minecraft.server.v1_5_R3.MinecraftServer.q(MinecraftServer.java:477)
2013-06-03 17:24:11 [SEVERE] at net.minecraft.server.v1_5_R3.MinecraftServer.run(MinecraftServer.java:410)
2013-06-03 17:24:11 [SEVERE] at net.minecraft.server.v1_5_R3.ThreadServerApplication.run(SourceFile:573)
2013-06-03 17:24:11 [SEVERE] Encountered an unexpected exception ConcurrentModificationException
java.util.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
at java.util.HashMap$KeyIterator.next(Unknown Source)
at net.minecraft.server.v1_5_R3.EntityTracker.updatePlayers(EntityTracker.java:151)
at net.minecraft.server.v1_5_R3.MinecraftServer.r(MinecraftServer.java:572)
at net.minecraft.server.v1_5_R3.DedicatedServer.r(DedicatedServer.java:226)
at net.minecraft.server.v1_5_R3.MinecraftServer.q(MinecraftServer.java:477)
at net.minecraft.server.v1_5_R3.MinecraftServer.run(MinecraftServer.java:410)
at net.minecraft.server.v1_5_R3.ThreadServerApplication.run(SourceFile:573)
last thing that possibly crashed your server...where is the report?