try this
# If True ActiveChar will not be able to Attack the Listed Npc Types.
DisableAttackToNpcs = True [ is false make it true and check it...i am not sure about this]
# List of NPC's that allow casting skills on them
# Any other type will not allow casting
AllowedNPCTypes = L2GrandBoss,L2Chest,L2FestivalMonster,L2Minion,L2Monster,L2Pet,L2RaidBoss,L2SiegeGuard,L2SiegeNpc,L2ControlTower,L2Artefact,L2PenaltyMonster,L2FeedableBeast,L2SiegeFlag,L2RiftInvader,L2Guard,L2GuardNoHTML