He was about to quit and reinstall the entire game (78 GB—a two-hour wait) when a buried comment on the IO Interactive forums caught his eye. Posted by an actual developer (badge verified): “For Direct3D 12 ‘Executable Not Found’ errors in Hitman 3, ensure that Windows’ Hardware-Accelerated GPU Scheduling is OFF. It conflicts with the game’s custom rendering pipeline for high-quality assets.”

The error wasn't a red box or a crash log. It was a single, clean line of white text on a black screen:

The executable might actually be missing or blocked by security software. Verify Integrity Steam Verification Tool Epic Games Verify option to redownload any missing Antivirus Exclusion

The most common cause of the Direct3D 12 error is driver instability with DX12. Switching to DirectX 11 is the most reliable fix.