Bug/Issue Question regarding invite codes

So my friend is having issues connecting to my hosted world and everytime he seems to try connecting the connection fails even with an invite code. So we got frustrated and decided to create a new world this time him hosting. However when he clicks the invite code button to invite me to his world, the code seems to not be able to be generated. It seems to be stuck on connecting for a long time. We were wondering if this is an connection issue with steam or the game server. Considering he can connect to the internet just fine and can play single player games

 

This is necessarily a firewall issue.
Turn your firewall off and your friend's off and it will work; just to prove its a firewall issue.
On linux those firewall rules are:
sudo ufw allow from 192.168.2.0/24 to any port 24642
sudo ufw allow out 26642

On Windows, it should translate the same
Unconditionally allow port 26642 out for any application (this is port forwarding)
But you must also provide inbound access (likely primarily for UDP handshake).
So for for that temporarily just allow everything in through port 24642.
In the longterm, add the IP to the computer you are connecting to (on the same LAN network) 192.168.2.whatever
Both computers have 24642 inbound rule but the IP should be different as explained above.
If it is not local LAN then the IP is dynamic and you can't create a rule with an IP filter.
You could try an application filter + port 24642, but I fear that this would fail.

 

I am having a similar issue, except the game isn't even showing inputting a code as an option. It literally only shows Host on her account as an option, nothing else. We've tried uninstalling and reinstalling both Stardew and Steam. All programs are up to date, and my Firewall is giving the program clearance both to send and receive information. I'm not sure what else it could be.