Vray Light Gen Not Working Apr 2026

They selected the dome, chose "Sunset," and hit .

The fix? Change the to a simple path like C:\VRayTemp (no spaces). Or, in newer versions, update to the latest hotfix.

Twenty minutes later, after sweating through the fix, Alex had a beautiful golden sunset. They delivered on time. But they never forgot: check the damn path spaces.

V-Ray Light Gen, in some versions, fails to write temporary HDRI preview files to a path containing a space. It silently fails. No error. Just a dead, dark dome. vray light gen not working

Alex’s Windows username was — with a space.

This is a frustrating moment for any 3D artist. Let me tell you a short, relatable story about this exact problem, then give you the most likely fix.

They Googled furiously: "vray light gen not working" — and found forum threads from 2018, vague mentions of "paths," and a buried comment about "Windows usernames with spaces." They selected the dome, chose "Sunset," and hit

It was 2 AM. Alex had a villa exterior due in 12 hours. The client wanted "dramatic, cinematic sunset lighting."

They restarted 3ds Max. Reset the scene. Tried "Morning." Same thing. The dome light stayed stubbornly black.

That was it.

Alex thought, "No problem. I'll use V-Ray Light Gen. Click a preset. Done."

The little progress bar appeared... crawled to 100%... and then… nothing. The Light Gen window went blank. The dome light in the viewport was still dark. No textures. No preview. Just silence.

Panic.