Describe the problem. Be as specific as possible!:

So, I downloaded Maplestory through Steam as the official downloader is pineappleed up, and I have a lot of games on Steam. However, every single WZ file has corrupted the day after I download it, resulting in me having to redownload it three times with no fix to the problem. I shut my computer down correctly, my Antivirus isn't messing anything up (I checked the logs), and all my other files are fine. What is going on, and what could be causing the problem. And how can I fix it? I have a pomegranatety download speed, so it takes about 4 hours to download the entire game, which is not how I want to spend my afternoon.

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