Quick answer: Fix Valheim connection issues with port 2456–2458 UDP, correct server password and open firewall.
If you landed here: Valheim dedicated server runs but nobody can join – "Disconnected", timeout or server not in list.
Open ports
ufw allow 2456:2458/udpRelated
Frequently asked questions (FAQ)
Which ports for Valheim dedicated server?
2456–2458 UDP (game + query). Open all three in firewall and hosting panel.
Valheim "Disconnected" or timeout?
Usually firewall, wrong port or server still starting. Wait 1–2 min after start.
Crossplay issues Steam/Xbox?
Check crossplay option at server setup. Steam and Xbox players need different join methods.