Check your worldsvr ini and disable the hack check options or increase the values of the time thresholds.
Code:
###################################
#### Hack checking options ####
###################################
UseHackcheckByTimeScope=1
UseCheckShopHack=1
UseCheckWarpHack=1
UseCheckWareHouseHack=1
UseCheckSkillCoolTimeHack=1
UseCheckDistanceSkillHack=1
UseCheckDeadStatActive=1
UseCheckDMZArea=1
UseCheckInventoryHack=1
UseCheckUserAttack=1
UseCheckDeadStatActive=1
ActiveDeadStatCount=30
SpeedHackCheckTime=10000
MaxAttackHackTime=300000
CheckSkillTimeHackScope=60000