I am getting an error when I'm just randomly crashing and the error says that I'm missing files that I need to download. I already downloaded the latest patch so I'm not sure what other files can I be missing.
Your antivirus can quarantine certain files. You'll want to disable it while you download then add the entire maple folder as an exception, or it will delete shit during later restarts. But i'm not 100% sure that's your problem, just a possible fix.
I'm running parallels windows XP so unless I'm wrong, I don't have any antivirus :O I can certainly double check on that though