Get the multiplayer mod up and running on Proton/Wine.

The Problem

Windows game mods aren't as straightforward on Linux, but luckily, it's only a matter of a few more steps in place of the usual process.

Update: Fixed! However, currently there is a bigger issue. Even though GTA Connected has "support for Windows XP and WINE", optimisations added to Proton/Wine over the years have caused issues getting it to work: namely, Fsync and Esync.

This guide goes over the installation of GTA Connected.

Setting up on Proton

1. Download old binaries compatible with GTA Connected
   • 1.0.8.0
   • 1.0.7.0
2. In your game library, right click the game > Manage > Browse local files
3. Unpack the Retail directory from the downloaded archive into the game directory, as such (no files should be overwritten):

   GTAIV
   ├── GTAIV.exe (unmodified)
   ├── Retail
   │   ├── GTAIV.exe
   │   └── (other files)
   └── (other files)
   

4. Install winetricks and protontricks to your system
   • Desktop system: Use your package manager if the packages are available on the repos or use install instructions from linked pages
   • SteamOS: Skip installing winetricks, use Flatpak-specific instructions to install protontricks
5. Download the latest GTA Connected client installer from the download section of the official website

6. Run the installer

   • GUI method: Open a file manager, navigate to where the file was downloaded, then right click > Protontricks Launcher, and from the list, select Grand Theft Auto IV (12210)

   • CLI method: Change directory to where the file was downloaded, then (adjust file name to the downloaded version):

     protontricks-launch --appid 12210 GTAC-x.x.x.exe

7. Either deselect "Run GTA Connected" in the installer, or close the client before proceeding

8. Navigate here (replace with the path to the Steam library where the game is installed):

   <steam-library>/steamapps/compatdata/12210/pfx/drive_c/users/steamuser/AppData/Local/Jack's Mini Network/Grand Theft Auto Connected

9. Set up a way to quickly launch GTA Connected

   • Shortcut method: Create a shortcut of Launcher.exe, name it "GTA Connected", and replace the Command field with this:

     protontricks-launch --appid 12210 Launcher.exe

   • Shell script method: Make a script like this:

     #!/bin/sh
     # Path to the GTA Connected client
     cd "/path/to/Grand Theft Auto Connected"
     
     # Launching
     protontricks-launch --appid 12210 Launcher.exe
     

10. Launch GTA Connected

11. In the process of selecting your game executable, make sure to select GTAIV.exe stored in the Retail directory from earlier
12. Play the game, hopefully it should work out of the box!

Troubleshooting

Mods

Edit: If even whitelisted mods used to fail to work, chances are you used the GTAIV/plugins directory. It's a search path now, so even mods from there will load just fine!

GTA Connected has a form of anti-cheat that only allows whitelisted mods. This, unfortunately, means that many mods won't work. It was also done to address the security concern in the event that a malicious client exploits the security downgrades provided by the typical ASI loader.

Launch arguments and commandline.txt not working

Edit: The issue with commandline.txt has been fixed! Using it is much preferred over using launch arguments, so do that if possible.

Note: This method does not work if GTA Connected client is restarted after an update. It must be started cleanly.

Steam launch arguments won't work because protontricks assumes the program you are trying to run isn't the game itself.

On the other hand, commandline.txt is supposed to be read by the game, but if the game is launched through GTA Connected, it is ignored.

Instead, modify the shortcut/shell script you use to launch GTA Connected by appending the launch arguments to Launcher.exe. The launcher will forward these arguments to the game.

Example:

(...)-launch --appid 12210 Launcher.exe -availablevidmem 2452.0

The game reverts to safe mode

This is caused by the game's faulty VRAM check that breaks if the GPU selected by the game has over ~2 GB of VRAM. Even if the same launch arguments are used as the ones to make the base game work properly, if the detected number is over 2 GB, this procedure must be followed.

Fortunately, if you are using a whitelisted mod that fixes this issue (ex. ZolikaPatch), doing the following is not necessary.

Procedure for 1.0.8.0 (absolute value)

Use this argument:

-availablevidmem 2452.0

Procedure for 1.0.7.0 (relative value)

1. Take note of the VRAM amount detected by the game in the Graphics menu (the second number in the Resource Usage line)
2. Divide 2452 with the number obtained from the previous step, only the first one or two decimals are enough
3. Use this argument (replace X.X with the number from the previous step):

-availablevidmem X.X

The game freezes on launch

Whenever this happens, kill GTAIV.exe.

Selecting Window mode under Tools > Game Settings... may make this freeze less likely to happen.

Attribution

Sources:

• arisu's discovery that Fsync and Esync have to be disabled
• Downgrading GTA IV to work on GTA Connected - GTA Connected Wiki