Logging in error {IMPORTANT PLEASE READ}

There is this extremely horrible bug that stopped me and my friend from playing jerryandharry. I'm still able to go on, but he can't he's an irl friend and he said he cannot acsess jerryandharry at all. He tried all the ips that were available, but none worked. So I went to his house to scope thing's out, and when he tried to go on, it said the same annoying message: "Network is unreachable" Well, he can acsess any server but jerry's. So I really want you to comment/reply to us wat we shall do. Anyway, have a nice day!

 

Perhaps try flushing your DNS?

 

Tell him to try and restart his router. This may be a chance of his network is low and may be needed to restart.
If that doesn't work, try and tell him to restart his computer. If it still occurs, refresh the server page or restart mc, along with the launcher.
If there is any other PCS on, there may be a chance that's slowing his internet down and unable to join.
Or it can be the server itself acting up as usual. Sorry if I couldn't be any help .u.

 

He has no texture packs, no mods, he's vanilla just like me.