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

Valheim Won't Launch? Here's the Fix

When Valheim won't launch — you get a black screen after the loading logo, the window opens and closes, or nothing happens at all — the fix is almost always a graphics-API or fullscreen mismatch. The single most effective move is forcing Vulkan or windowed mode from Steam launch options.

Exact details for Valheim

Best launch option (black screen)
-force-vulkan
Fallback launch option
-windowed -noborder
Force resolution
-screen-width 1920 -screen-height 1080 -screen-fullscreen 1
Common cause of black screen
NVIDIA G-Sync + fullscreen conflict — disable G-Sync for Valheim

Error codes

Black screen after Steam logo The game process runs but never renders

Cause: Fullscreen/GSync conflict or a DirectX-vs-Vulkan mismatch.

Fix:
  1. Add -force-vulkan to Steam launch options (Properties > General).
  2. If that fails, try -windowed -noborder to bypass the fullscreen handshake.
  3. Turn off G-Sync in the NVIDIA Control Panel for Valheim.
  4. Alt+Enter once the black screen appears to force a window redraw.
Window opens then closes / instant crash Valheim exits before the menu loads

Cause: Corrupt files, outdated GPU driver, or a bad mod.

Fix:
  1. Verify integrity of game files in Steam (Installed Files tab).
  2. Update the GPU driver, then reboot.
  3. Remove or disable ALL mods (BepInEx) and delete leftover plugin DLLs.
  4. Run Steam and Valheim as Administrator.
Wrong resolution / off-screen window The window renders outside the visible area

Cause: A saved resolution larger than the monitor.

Fix:
  1. Force a safe size: -screen-width 1920 -screen-height 1080.
  2. Add -screen-fullscreen 1 to lock fullscreen behaviour.
  3. Delete the local prefs so Valheim regenerates display settings.
  4. Set the desktop to the monitor's native resolution before launching.

Fixes that work for most Valheim errors

  1. Add -force-vulkan to Steam launch options first — it fixes most black screens.
  2. If still black, try -windowed -noborder.
  3. Turn off NVIDIA G-Sync for Valheim.
  4. Force resolution with -screen-width 1920 -screen-height 1080.
  5. Verify game files and update GPU drivers.
  6. Remove all BepInEx mods and run as Administrator.

FAQ

What launch option fixes Valheim's black screen?

-force-vulkan is the most reliable fix — add it in Steam under Properties > General > Launch Options. If the black screen persists, switch to -windowed -noborder to skip the fullscreen handshake entirely.

Why does Valheim open a black window then hang?

Usually a G-Sync/fullscreen conflict. Turn off G-Sync for Valheim in the NVIDIA Control Panel, or press Alt+Enter on the black screen to force a redraw, then set windowed mode.

Valheim crashes instantly after a mod update — why?

A stale BepInEx plugin. Disable all mods, delete leftover DLLs in BepInEx/plugins, and verify game files in Steam before re-adding mods one at a time.

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