java.lang.ClassNotFoundException: l1j.server.server.model.Instance.L1EventTowerInstance

        at java.net.URLClassLoader.findClass(Unknown Source)

        at java.lang.ClassLoader.loadClass(Unknown Source)

        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)

        at java.lang.ClassLoader.loadClass(Unknown Source)

        at java.lang.Class.forName0(Native Method)

        at java.lang.Class.forName(Unknown Source)

        at l1j.server.server.model.L1Spawn.<init>(L1Spawn.java:75)

        at l1j.server.server.datatables.NpcSpawnTable.fillNpcSpawnTable(NpcSpawnTable.java:104)

        at l1j.server.server.datatables.NpcSpawnTable.<init>(NpcSpawnTable.java:42)

        at l1j.server.server.datatables.NpcSpawnTable.getInstance(NpcSpawnTable.java:31)

        at l1j.server.server.GameServer.initialize(GameServer.java:376)

        at l1j.server.Server.startGameServer(Server.java:114)

        at l1j.server.swing.ServerStart.<init>(ServerStart.java:46)

        at l1j.server.swing.chocco$23.run(chocco.java:767)

        at java.lang.Thread.run(Unknown Source)

선생님들 cmd에서 이런오류뜨는데 문제가 뭘까요..