[Help] Npc_table

[Mage]

Yesterday i modified more mob and today the server gives more Error:

NPCTable: Error creating NPC table.
java.lang.IllegalArgumentException: String value required, but not specified
at net.sf.l2j.gameserver.templates.StatsSet.getString(StatsSet.java:372)
at net.sf.l2j.gameserver.templates.chars.L2NpcTemplate.<init>(L2NpcTemplate.java:154)
at net.sf.l2j.gameserver.datatables.NpcTable.fillNpcTable(NpcTable.java:388)
at net.sf.l2j.gameserver.datatables.NpcTable.restoreNpcData(NpcTable.java:83)
at net.sf.l2j.gameserver.datatables.NpcTable.<init>(NpcTable.java:61)
at net.sf.l2j.gameserver.datatables.NpcTable.<init>(NpcTable.java:45)
at net.sf.l2j.gameserver.datatables.NpcTable$SingletonHolder.<clinit>(NpcTable.java:641)
at net.sf.l2j.gameserver.datatables.NpcTable.getInstance(NpcTable.java:54)
at net.sf.l2j.gameserver.GameServer.<init>(GameServer.java:272)
at net.sf.l2j.gameserver.GameServer.main(GameServer.java:599)

NPCTable: Drop data for undefined NPC. npcId: 12774
NPCTable: Drop data for undefined NPC. npcId: 18001
NPCTable: Drop data for undefined NPC. npcId: 18001
NPCTable: Drop data for undefined NPC. npcId: 18001
NPCTable: Drop data for undefined NPC. npcId: 18001
ecc

ecc

ecc...

First to id 12774 there is (12621,12621,'Wyvern',0,'',0,'Monster.wyvern',60,80,70,'male','L2Pet',40,3862,1722,11.85,2.78,40,43,30,21,20,25,0,0,1335,470,780,440,282,0,333,0,0,0,88,187,'NULL',0,0,0,'LAST_HIT',0,0,0,'fighter','false'),

But i don't remember which npc i modified...

Is there a method to find the problem? in which npc is there the error?

Thank

[Mage]

Solved.

at net.sf.l2j.gameserver.templates.chars.L2NpcTemplate.<init>(L2NpcTemplate.java:154)

An npc have Tamplate ID 0..