GTA V’s shader compiler needs ample virtual memory. A small pagefile triggers the error.
Tessellation hugely impacts shader complexity. Disabling it in-game often resolves ERR_GFX_D3D_SHADER1 completely. errgfxd3dshader1 best
you are playing so I can provide more specific troubleshooting! How To Fix GTA 5 Not Launching Issue Error - Step By Step GTA V’s shader compiler needs ample virtual memory
Add these command line arguments in your launcher’s advanced settings: errgfxd3dshader1 best