I'm glad it helped. Although, not much after posting this, i have seen the same error message in a spell or ability's description, but didn't take any screenshot this time. This may be linked, i can't tell unfortunately. Would it be of any use i bring a screenshot of other messages of this kind ?
Is this amulet so powerful i'm not supposed to see its effects ? This amulet is sold by Echalas at the upper left corner of miner's way in the city of Neketaka, I'd try to traduce its name by "Amulet of protection against rotting" or so. ( sorry for french version ^^' )