๐ŸŽฎ Game Error Codes What it means & how to fix it

Baldur's Gate 3 Can't Join Multiplayer? Here's the Fix

Most Baldur's Gate 3 "can't join session" failures come down to three things: the two players are on different game versions or platforms, one of you has mods the other doesn't, or the Larian/host connection is being blocked. The fastest fix: make sure both players are on the exact same patch and have identical mods (or none), then have the host send the invite through Steam/the in-game friends list rather than a LAN connection. Steps below, in order.

Baldur's Gate 3 โ€” Direct Connect & the mod-mismatch fix

Direct Connect workaround
fully quit Steam > run \Baldurs Gate 3\Launcher\LariLauncher.exe > load save > pause menu > Multiplayer > cog > enable Direct Connect
Mod-mismatch fix
delete the 'Mods' and 'Public' folders in ...\steamapps\common\Baldurs Gate 3\Data (safe to remove) to clear the launcher data-mismatch error
Join workaround
start a NEW save, have everyone join, then host loads the original save once all are in
LAN alt
Main menu > Multiplayer > LAN tab; enable LAN connections in Lobby Settings

Last verified: September 2026

Error codes

Failed to join session / session no longer available The client reached the host's lobby but could not complete the join

Cause: A version mismatch after a patch, mismatched mods, or the invite expiring before you accept it.

Fix:
  1. Confirm both players are on the same BG3 patch (Steam usually updates automatically โ€” restart Steam to force it).
  2. If either uses mods, both must have the SAME mods and load order, or both must play with mods fully disabled.
  3. Have the host re-send a fresh invite from the in-game multiplayer menu right before you accept.
  4. Cross-play: make sure both are on compatible platforms and signed into their Larian accounts.
Connection timed out / stuck on connecting The join request never reaches the host

Cause: Firewall or NAT blocking the peer connection, or a LarianๆœๅŠก auth hiccup.

Fix:
  1. Allow bg3.exe and bg3_dx11.exe through Windows Firewall on both PCs.
  2. Set NAT to Open (enable UPnP on the router) so peer-to-peer can be brokered.
  3. Sign out and back into your Larian account in-game to refresh auth.

Fixes that work for most Baldur's Gate 3 errors

  1. Match the patch: both players on identical BG3 builds; restart Steam to pull any pending update before hosting.
  2. Match mods exactly, or disable all mods on both sides โ€” a single host-only mod silently blocks the join.
  3. Invite through the in-game multiplayer menu or Steam friends list rather than direct IP/LAN.
  4. Allow bg3.exe and bg3_dx11.exe through the firewall and antivirus on both machines.
  5. Enable UPnP / set Open NAT on the host's router so the co-op session can connect.
  6. Verify game files (Steam > Properties > Installed Files > Verify) if a patch left files broken.
  7. If it broke right after an update, both players fully close and relaunch BG3 so both are on the same synced build.

FAQ

Why can't I join my friend's Baldur's Gate 3 game?

Usually you're on different game versions or have mismatched mods. Confirm both are on the same patch, have identical (or no) mods, and accept a fresh invite from the in-game multiplayer menu.

Do mods break BG3 multiplayer?

Yes, if they differ between players. Both players must run the same mods in the same load order, or both must disable mods entirely โ€” a host-only mod will block the join.

How do I fix 'failed to join session' in BG3?

Restart Steam to sync the patch on both PCs, match or remove mods, allow bg3.exe through the firewall, and have the host send a new invite right before you accept.

Does BG3 need port forwarding for co-op?

Not usually โ€” invites are brokered through the platform. If joins keep timing out, enable UPnP or set an Open NAT on the host's router instead of manual port forwarding.

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