He isn't able to reach my server.
He isn't able to reach my server.
It's a fascinating scenario you're facing. Would you be comfortable revealing your router brand? Have you considered reaching out to some of your acquaintances to see if they can join in? It might be related to a security concern preventing them from connecting.
Old Java releases caused issues before reinstalling Windows, but after updating Java, the latest Minecraft functions properly. The problem might be a bug in the newest version preventing players from joining.