Fixes

Every fix page follows the same rule: work the causes in order of likelihood, one minute per step. Start from the symptom you actually see.

"Failed to connect to server"

• Failed to connect — full checklistServer status, address, version, firewall, then the rarer causes. Split into player-side and owner-side halves.

"Firewall error"

• Firewall error fixWindows Defender (including the both-networks checkbox), third-party antivirus, and router filtering.

"Server failed to boot" (you host)

• Server failed to bootPort in use, config corruption, outdated build after a patch, mods, world damage — mapped to what each looks like in the log.

"Multiplayer not working" (friends and invites)

• Multiplayer not workingVersion mismatch in the group, NAT and home networks, and how to isolate whose end is broken.

Something else broken?

• Game updates can change behavior mid-play — check the update tracker before assuming it's you.
• Mods cause failures that look like network errors — mod browser, conflicts section.
• Try the site search with the exact error text.