Maybe because there already is an entry called Acbr in another file, and it just isnt a skill in abilitydata.slk anymore. Try extracting all the raceabilityfunc.txt into one folder, then search for files containing the text "Acbr". Also, you could just change the code, something with numbers in it usually works. For example, mine are Sin1 to Sin9, so i`ll never have that happen. | 
