make sure its in a v83 Maplestory folder. and check to see if firewall is blocking it. ALSO on my computer the first time i ran galaxyms i got a pop up asking me to run or not to run the program, maybe you clicked no and the "do this for all future encounters" box was checked? or your fils are corrupted ( get clean .wz files) or redownload the client, or restart your computer, internet, or both.