Buffer Overrun

Hey guys so um while. i was trying find the problem with my lvl 60 jc somehow i got the Over time and Space # 1 quest and did that but after i did it and went to turn it in to Town Chief Roumenus I get this error Saying "Buffer Overrun Detected" then my p sever just close on it's own when i open my server and try to do 60 job change it wont let me no it wont let me get quest. could someone help me please?. I look it up what it means and it just say someone trying to hack my computer which i doubt it. please help thanks (hate when i have to post a new thread for everything..)