We are unable to open your game client

Just downloaded the game files, double clicked the patcher, and that error pops up.
I restarted my computer and has the same error.

 

Same here..

 

Do you guys have official maplestory installed?

 

Nope, I don't.

 

That happened to me when I had GMS installed, not sure what to do then wait for GM or other experienced player to answer

 

Figured it out!
Before you open your setup and install it, turn off any antivirus software.
I installed it twice and it wouldnt work, the desktop shortcut was an unreadable file. As soon as I installed it with no antivirus on, it worked immediately. Like, double click and into gamr instantly.

 

Yeah, I managed to get it working a couple of minutes ago, had the same problem^^"