In our weekly update we included an engine upgrade to Unreal Engine 4.27. An unfortunate side-effect of this update meant that players could no longer rejoin multiplayer prospects in progress.
Hotfixes are disruptive due to downloads
We do apologize for doing the hotfix, as we know it is disruptive with how the downloads work and some users experience long times where Steam has to verify the entire game. Unfortunately we really do need to get this change out, as it is badly impacting some players.
Fixed: Inability to Join Multiplayer Sessions In Progress
Details of problem:
Our host session parameters were not properly brought across during engine upgrade.
We were specifying that you could ONLY join via Steam friends thus when searching for old sessions none would populate. Would work first time due to crowbar join flow available only to the session browser as we had all required session data right there.
Learnings:
1. Rejoin flow MUST be included as part of our default testing loop. Especially when upgrading engine versions / upgrading match making plugins.
2. Keep locally staged builds relevant on remote PCs so we can be quicker to step through and debug these issues.
A big thank you to the engineers who worked today's public holiday to resolve the issue before the weekend.