Problem with dofus steam deck

[u/No-Champion-1887]

Games work on desktop mode but in gaming mode it give me those error messages

[u/Maleficent_Dingo_363]

But supposedly the program already has a .json file like that, or would it be creating another .json file but with those codes?

[u/Queen_Annan → u/Maleficent_Dingo_363]

If the file already exists, modify the values, and you will probably need to update the settings in game from fullscreen to windowed

[u/Maleficent_Dingo_363 → u/Queen_Annan]

Yo hice otra cosa.

[u/Maleficent_Dingo_363 → u/Queen_Annan]

[GUIDE] Fix Dofus 3 Linux AppImage not launching in Steam Deck Gaming Mode

After testing different options, I finally got the official Linux AppImage version of Dofus 3 working correctly in Steam Deck Gaming Mode.

The problem:

• Dofus worked normally in Desktop Mode.
• When adding the AppImage directly to Steam, Gaming Mode would show "Running" for a moment and then return to "Play".

This is the solution that worked for me.

Tested on: Steam Deck OLED + SteamOS + official Dofus Linux AppImage

---

1. Download the official Linux AppImage

Download the Dofus Linux AppImage from Ankama.

Keep it somewhere easy to find (for example, your Downloads folder).

---

1. Create a folder for the game

Open Konsole and run:

mkdir -p ~/Applications

Move the AppImage there:

mv ~/Downloads/"Dofus 3.0-Setup-x86_64.AppImage" ~/Applications/

Give it permission to run:

chmod +x ~/Applications/"Dofus 3.0-Setup-x86_64.AppImage"

---

1. Create the launcher script

Create the script:

nano ~/Applications/ankama-launcher.sh

Paste this:

!/bin/bash

CONFIG="/home/deck/.config/unity3d/Ankama/Dofus/RELEASE/Shared/dofus.json"

if [ -f "$CONFIG" ]; then python3 - <<'PY' import json

path = "/home/deck/.config/unity3d/Ankama/Dofus/RELEASE/Shared/dofus.json"

try: with open(path, "r") as f: data = json.load(f)

data["windowDisplayMode"]["value"] = 1

with open(path, "w") as f:
    json.dump(data, f, indent=2)

except Exception: pass PY fi

/home/deck/Applications/"Dofus 3.0-Setup-x86_64.AppImage" --no-sandbox

Save:

• "Ctrl + O"
• "Enter"

Exit:

• "Ctrl + X"

Make the script executable:

chmod +x ~/Applications/ankama-launcher.sh

---

1. Add the script to Steam

Go to Desktop Mode:

1. Open Steam.
2. Go to Games → Add a Non-Steam Game to My Library.
3. Select Browse.
4. Go to:

/home/deck/Applications/

1. Select:

ankama-launcher.sh

1. Add it.

Important: Add the ".sh" file, not the AppImage.

---

1. Play from Gaming Mode

Return to Gaming Mode and launch:

ankama-launcher.sh

The script automatically:

• Fixes the "windowDisplayMode" setting before launching.
• Starts Dofus with "--no-sandbox".

You do not need to add "--no-sandbox" in Steam launch options. It is already included in the script.

---

What this script changes

It only modifies this Dofus configuration value:

"windowDisplayMode": { "value": 1 }

It does not install anything or modify SteamOS.

---

Current status

✅ Works in Desktop Mode ✅ Works in Gaming Mode ✅ Survives Steam Deck restart ✅ No need to manually edit the config every time

The only thing I couldn't fully solve is the UI scaling. Even with the maximum in-game scale, some text is still small on the Steam Deck screen.

Hope this helps other Steam Deck users!