How to fix error driver-irql-not-less-or-equal in Lost Ark

Solution Steps

1. 1 Run Lost Ark as Administrator. Navigate to the game folder, right-click the .exe → Properties → Compatibility → check 'Run this program as an administrator' → Apply. This gives Lost Ark full system access and fixes permission-related crashes.
2. 2 Update Windows to the latest version. Settings → Windows Update → Check for updates. Install ALL updates, especially 'Optional' driver updates. Lost Ark requires the latest Windows components for stability.
3. 3 Disable fullscreen optimizations. Right-click Lost Ark.exe → Properties → Compatibility → check 'Disable fullscreen optimizations' → Apply. This prevents Windows from interfering with the game's rendering pipeline.
4. 4 Install Lost Ark on an SSD if it's currently on an HDD. Slow disk reads during gameplay cause asset streaming stutters that can cascade into crashes. An SSD eliminates this bottleneck.
5. 5 Check your RAM stability. Press Windows key + R, type 'mdsched.exe' and press Enter → Restart now. Faulty RAM causes random crashes in Lost Ark that are impossible to reproduce consistently.
6. 6 Temporarily disable your antivirus real-time protection and test Lost Ark. Add the game folder to antivirus exclusions. Security software sometimes quarantines game files or blocks their execution.
7. 7 Lower Lost Ark graphics settings temporarily. Set everything to Low/Off, disable Ray Tracing, disable DLSS/FSR. If crashes stop, increase settings one by one until you find the problematic setting — usually shadows, textures, or ray tracing.
8. 8 If Lost Ark still crashes: uninstall the game, delete all remaining folders in SteamApps\common and %LOCALAPPDATA%, restart your PC, reinstall. This clean slate approach fixes stubborn corruption that verification misses.