[Help]Error in instance spawn

[DLDL]

i have this error , please help me fast , i don't know how this problem happen


[29.05.18 05:39:27:607] ERROR npc.NpcTemplate: Unable to create instance of NPC 13042
java.lang.IllegalArgumentException
at sun.reflect.GeneratedConstructorAccessor53.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at l2ro.gameserver.templates.npc.NpcTemplate.getNewInstance(NpcTemplate.java:164)
at l2ro.gameserver.model.Spawner.doSpawn0(Spawner.java:203)
at l2ro.gameserver.model.HardSpawner.doSpawn(HardSpawner.java:54)
at l2ro.gameserver.model.Spawner.init(Spawner.java:129)
at l2ro.gameserver.instancemanager.SpawnManager.spawn(SpawnManager.java:202)
at l2ro.gameserver.instancemanager.SpawnManager.spawnAll(SpawnManager.java:163)
at l2ro.gameserver.GameServer.<init>(GameServer.java:246)
at l2ro.gameserver.GameServer.main(GameServer.java:486)