When a new file has been made and makes changes to your pc files, any good antivirus program will detect whats happening and most likely delete the file if it thinks its malicious.Just because your antivirus thinks is malicious doesn't neccesarily mean it is. To avoid this altogether you need to allow your programs under your antivirus's firewall settings. The best thing to do when the server ever updates its launcher or files is to disable temporarily your antivirus so that it won't delete any updates to the game as soon as it happens. From there go back to your antivirus program to turn back on and allow any new associated files with phantasy star online. If you use norton antivirus, another thing to do is click on the new files and then you'll find something called norton file insight. When you click on norton file insight make you you press the trust button on the new files.