Far Cry 3 would launch on Steam + Ubisoft Connect, then crash immediately.

The issue was:

>

Check with:

glxinfo -B

If you see:

llvmpipe (LLVM ...)

You must fix GPU rendering first (OpenGL to Intel GPU) before games will work properly.

Even though:

• Intel GPU was detected
• Vulkan worked correctly
• Drivers were installed

OpenGL was falling back to software rendering.

In my case, the fix was:

>

Step by step solution.

1. Verify Intel GPU is detected

sudo lshw -c video

Look for:

• Intel Iris / UHD Graphics
• example: driver= i915

2. Check GPU render device exists

ls -l /dev/dri

You should see like:

• card0 or card1
• renderD128(make sure you have it)

3. Make sure your user has GPU permissions (IMPORTANT)

Check groups:

groups

You should see:

• video
• render

If missing, add them:

sudo usermod -aG video $USER
sudo usermod -aG render $USER

Then reboot:

sudo reboot

This allows access to /dev/dri for GPU acceleration.

4. Install Mesa utilities

sudo apt install mesa-utils

5. Check OpenGL renderer (MOST IMPORTANT TEST)

glxinfo -B

Wrong:

llvmpipe

Correct:

Mesa Intel(R) UHD Graphics (ICL GT1)

6. (Optional) Reinstall graphics stack

This ensures Mesa + drivers are clean:

sudo apt update
sudo apt install --reinstall \
libgl1-mesa-dri \
libglx-mesa0 \
libegl-mesa0 \
libgbm1 \
libdrm2 \
mesa-vulkan-drivers

7. Switch from Wayland → Xorg (THIS IS THE FIX)

This changed OpenGL backend behavior, and stopped llvmpipe fallback.

Steps:

1. Log out
2. On login screen:
   • Select your user
   • Click ⚙️ gear icon (bottom right)
3. Select:

​

Ubuntu on Xorg

1. Log in again

8. Confirm session type

echo $XDG_SESSION_TYPE

its expected to be:

x11

9. Reset Steam Proton prefix (really important)

Old config was created while GPU was broken:

rm -rf ~/.steam/steam/steamapps/compatdata/220240

As a result:

• no more llvmpipe
• Intel GPU properly used
• Far Cry 3 launches correctly

So, the real solution is:

>

I had help from AI to write all these steps. But this solution worked for me.