General

I had the same problem but I just left it alone for an hour or so and it finished on its own.

Navigate to your "MapleStory" Folder and run the "GameLauncher." Click "Play" like usual and let it update. Should work just fine using the new launcher after that.

have u tried reinstalling launcher?

mines just sat there for like 5minutes, then it started downloading the update.

Yep. I've tried many things to fix it like factory reset, steam and other things yet nothing happened. Time to send tickets to nexon