cuotel

other than doing that there shouldn't be any other issue. you might have to create a new world as well as changing it to peaceful... just a thought

I believe i know your problem just from the beginning of the error message " ic2.core.IC2.onLivingSpecialSpawn" this "specialspawn" is a mob added by IC2 obviously, and it is a mob that appears for a Halloween event coded in IC2. in order to fix this you must change the gamemode to peaceful on the server. this event will occur until the believed date of November 1st 2013.