🎮 Game Error Codes What it means & how to fix it

Little Nightmares III Fatal Error — 'The UE4-SMG031MP Game Has Crashed and Will Close'

Little Nightmares III runs on Unreal Engine with Ray Tracing via Lumen, and its internal project name is SMG031MP — so its signature crash is 'The UE4-SMG031MP Game Has Crashed and Will Close' LowLevelFatalError, usually a DXGI device-removed crash tied to Ray Tracing. The fix most players miss: turning Ray Tracing off and forcing Windows 8 compatibility mode. Here is each cause and the fastest fix.

Error codes

'The UE4-SMG031MP Game Has Crashed and Will Close' (LowLevelFatalError) Unreal Engine threw a LowLevelFatalError — SMG031MP is Little Nightmares III's internal UE project name

Cause: A DXGI 'device removed/hung' event, driven mainly by Ray Tracing / Lumen on unstable GPU drivers.

Fix:
  1. Turn Ray Tracing OFF in the graphics menu — Lumen ray tracing is the confirmed trigger of the DXGI device-removed crash behind UE4-SMG031MP.
  2. Right-click LN3.exe -> Properties -> Compatibility -> run in Windows 8 compatibility mode; this clears the DXGI Device Removed fatal error for many players.
  3. Clean-install the latest GPU driver with DDU (Display Driver Uninstaller), then the newest Nvidia/AMD build, and rebuild shaders.
LowLevelFatalError DXGI_ERROR_DEVICE_REMOVED / Device Hung The GPU stopped responding and Windows reset the display driver mid-frame

Cause: GPU thermal/power spike, factory overclock, or too-aggressive graphics settings.

Fix:
  1. Force the game into DirectX 11 by adding -dx11 to the Steam launch options (Properties -> General -> Launch Options).
  2. Reset any GPU factory overclock to stock and cap the frame rate to reduce power spikes.
  3. Lower Texture, Shadow and View-Distance quality one notch to cut VRAM pressure.
Crash on the shader-compilation / startup screen Game dies while building its shader cache on first launch

Cause: Corrupted DirectX/GPU shader cache or a stale driver.

Fix:
  1. Clear the NVIDIA DXCache (C:\Users\<you>\AppData\Local\NVIDIA\DXCache) and the DirectX Shader Cache via Disk Cleanup, then relaunch.
  2. Verify integrity of game files in Steam (Properties -> Installed Files).
  3. Install the latest Microsoft Visual C++ Redistributables (x86 + x64).

Fixes that work for most Little Nightmares III (PC / Steam, Unreal Engine, internal name SMG031MP) errors

  1. Turn off Ray Tracing and run the .exe in Windows 8 compatibility mode — the two fixes that clear most UE4-SMG031MP DXGI crashes.
  2. Clean-install the latest GPU driver with DDU and install the newest Microsoft Visual C++ Redistributables (x86 + x64) plus the DirectX End-User Runtime.
  3. Verify game files in Steam and clear the DirectX/NVIDIA shader cache, then relaunch to rebuild.

FAQ

Is 'UE4-SMG031MP' a virus?

No — SMG031MP is simply Little Nightmares III's internal Unreal Engine project name. The message is UE's generic LowLevelFatalError wrapper, here almost always a Ray-Tracing-driven DXGI device-removed crash.

What is the single most effective fix?

Turning Ray Tracing off, and if that isn't enough, running the game in Windows 8 compatibility mode — both target the DXGI device-removed event that produces the UE4-SMG031MP fatal error.

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