[0.16.51] Couldn't establish communication with server...

[Semthepro]

Hello there, again!

I want to connect with a friends multiplayer game that i could join some weeks ago fine but now it suddenly doesnt works. I tried everything from portforwarding to disappling the firewall and the antivirus and even changing the NAT type but nothing worked. I literally found NOTHING similar somewhere in the internet and i am really helpless as i tried everything humanly possible considering networking. Other friends can join his game fine without doing anything trough factorio and steam directly. I have no idea what to do next.

Help is appreciated! Best Regards
Semthepro

PS:[This is a technical problem, so it cant be off-topic]

[Loewchen]

I posted the wrong link before...
The error message means that you did not receive a confirmation message from the server, post the logs of server and client of the same session for further info, see my signature.

[nunyabus9]

I'm having the same issue, updated factorio, deleted old saves, ported router, what did I miss?
Here is the log
"ip addy was changed"
thanks for any help