Corrupted installation files can prevent shaders from loading.
Graphics cards lacking the necessary instructions for the game's engine.
If the error started after a recent update, try reverting to a driver version from 2-3 months ago. 4. Disable Overlays and Third-Party Tools errgfxd3dshader1 work
While "update your drivers" is standard advice, RDR2 is sensitive to specific versions.
D3D errors are often triggered by software that "hooks" into the graphics pipeline. Try disabling: Steam/Discord Overlays. MSI Afterburner or RivaTuner Statistics Server. Performance monitoring software. Try disabling: Steam/Discord Overlays
Misalignment between the game's API settings and your hardware.
Settings > My installed games > RDR2 > Verify Integrity . Article Summary Table Potential Fix Shader Cache Delete sga_ files in the Settings folder. Graphics API Toggle between Vulkan and DX12. Hardware Disable GPU overclocking/undervolting. Software Disable overlays (Discord, Steam, GeForce Experience). errgfxd3dshader1 work
Open the menu in-game (or edit system.xml in the folder mentioned above). Find the section.