internal exception java.net.socketexception connection reset

I bought minecraft java edition Realm and my firend just can't play in this realm. When he connects he is thrown out with a text "internal exception java.net.socketexception connection reset". I have searched all the forums and there is no permanent solution for it. It turns out this is a server connection problem that is only resolvable by the Realms (Minecraft) developer. There is no problem with java or firewall.