Try to reinstall the game and make sure that your antivirus don't take risk bcoz based on my experience i face the same problem but i delete my McAfee antivirus and then reinstall the game and now its fine. Windows defender is enough. If its apply same issue then mail to support@infinitymu.net
I've just help someone with the same problem of yours, Snoke- problem/error only occurred/pop-out when using Pingzapper, if he did not use PZ, it runs without any problem/error. I also did try this [Solution] Can not Connect to FTP and problem/error still there + using PZ, what i did to fix the problem he had, is uninstall the game client. And re-download it using IDM(Internet Download Manager) cause i think maybe the installation client is corrupt and told him that i will download a fresh copy of the game client here; FTP download and install, then update the game via Auto Update, after that there will be more update via mu launcher, let it finish itself. The game launcher will restart when you click "Connect" so that the game files will take effect and then re-try running the game w/ pingzapper and the problem/error does not pop-out anymore. If you do need help via teamviewer, add me in skype, here is my user id: lord.of.chix