[HELP] Some people are unable to connect. v83

Hello,

I have my dedicated server hosted in germany, running my maplestory moopledev v83 server.

Everything is running perfectly, I can launch the game at home and it works fine..

BUT

When my friend Downloads the exact same game version from same link. And locate my localhost to hes gms folder. Notthing happens? it just circles around and thinkin... and then suddently it stops... Notthing launches...

Is there a logical explanation for this issue? since we have the same setup... I can't see the problem?

I am able to connect to your server with the localhost i provided you lol.
The problem is at his side.

He is able to ping the server.

What could the issue be?

There's a chance he has a loopback adapter connecting to a different IP.

Thank you everyone for your answers!

Problem Solved. Please close threat.

Solution: Client local firewall on hes router was set to Advanced, blocking trafic from specific ports required for MS.
This is now solved by reduce security level on the router.