Vray Light Gen Not Working May 2026

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.

They restarted 3ds Max. Reset the scene. Tried "Morning." Same thing. The dome light stayed stubbornly black. vray light gen not working

Panic.

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. V-Ray Light Gen, in some versions, fails to

Alex’s Windows username was — with a space. V-Ray Light Gen

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

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