We set up a minecraft server yesterday. I did most of it with a helpdesk guy from our ISP so all seems to be working. Port forwarding set up on router, static IP, port open.
The problem we have is that my son and his friend cannot connect at the same time. They can both connect independently - but basically whoever is first to connect is the only one playing. I have managed to play with my son via my computer (I'm hosting the server). They both have the external IP address and minecraft port number.
The player count is set to 20. White list is off.
Error message is io.netty.channel.abstractchannel.
I just added a port exception to my firewall. Although I'm not sure that's the issue as they can connect, just not together.
I have googled this but not found an exact similar error.
I'm not overly techie but I'm great at following instructions!