Just Cause 3: Multiplayer Mod - Update 1.0.8
2026-08-19Just Cause 3: Multiplayer Mod - Update 1.0.8 Hey everyone, Update 1.0.8 is now live on Steam. 1.0.7 was the first step in bringing JC3:MP back: getting the client running again on modern systems, updating the UI, and opening the door for active development again. 1.0.8 is the next step. This update brings the server forward with the client, replaces one of the oldest parts of the multiplayer stack, restores server banners, improves the join flow, and lays down a much better foundation for future gameplay work. This is not the update where every long-standing issue disappears overnight. It is the update that makes the next updates much more realistic. The mod should be easier to host, easier to diagnose, and easier for us to keep improving from here. In short: JC3:MP is moving again. Important This is a required update for both clients and servers.
Read the full notes
1.0.8 clients cannot join 1.0.7 servers, and 1.0.7 clients cannot join 1.0.8 servers. If you host a server, please update your server files before players on the new client try to join. Highlights • Added the refreshed 1.0.8 server build • Moved multiplayer connections to Steam's modern networking system • Restored server banners in the server browser • Improved server join, timeout, and disconnect handling • Improved package download and cache handling while joining servers • Improved player, vehicle, weapon, object, checkpoint, and world replication • Improved server logs for connection and sync issues • Continued the client and server cleanup needed for future updates Changelog Client • Updated the multiplayer connection flow • Improved timeout handling when a server cannot be reached • Improved behavior when a join attempt fails • Improved cleanup when leaving multiplayer • Improved cleanup when disconnecting during loading • Improved connection status handling during package checks • Improved package download status while joining servers • Improved handling of cached packages • Restored server banners in the server browser • Improved server list presentation with banner support • Improved main UI state handling during connect/disconnect flows • Improved input ownership around multiplayer UI screens Multiplayer Sync Large parts of this have been entirely rewritten and re-architected, this should bring a much more consistent and correct experience to player and vehicle replication. Server • Added the updated 1.0.8 server build • Updated server networking to match the new client connection system • Improved player join and leave handling • Improved server-side disconnect cleanup • Improved package transfer reliability • Improved package transfer failure reporting • Restored server banner/advertisement support • Improved entity streaming and visibility handling • Improved world synchronization flow • Improved scripting diagnostics • Improved script warning messages in several cases • Improved logging for connection failures • Improved logging for sync-related issues Server Owners • Servers must be updated to 1.0.8 for 1.0.8 clients to connect • If players cannot join, first verify that both client and server are on 1.0.8 • Server banners are supported again • Package downloads should be less likely to stall • File transfer failures should be easier to identify • Connection problems should leave clearer information in the logs • The new server build should be a better base for future hosting and debugging Fixes And Polish • Improved join flow reliability • Improved disconnect flow reliability • Improved package cache verification display • Improved handling of failed package transfers • Improved server browser presentation • Improved multiplayer UI state cleanup • Improved scripting warnings for server developers Looking Ahead JC3:MP has been carrying a lot of old code for a long time. Some of it made even simple fixes harder than they should be. With 1.0.8, one of the biggest pieces has been replaced, the server is back in the release cycle, and the project is in a much better position for the work still ahead. There is still plenty to do, but this update is a major step toward making JC3:MP easier to maintain, easier to host, and better to play. Thank you to everyone testing builds, hosting servers, reporting bugs, and giving feedback. More is coming.