Game won't start after the last minor patch

Disappears?

Sounds like something an anti-virus might do.

I don't think so. I disabled Windows Firewall and Windows Defender last time I reformatted, and I've never installed AV software on my computer.

I'm wondering if it's some issue with my PC's admin account or something going wrong with UAC. After patching I am also barred from deleting the Nexon/Maplestory folders until Maplestory.exe erases itself. Says I need permission from an administrator...