It was 2 AM. Alex had a villa exterior due in 12 hours. The client wanted "dramatic, cinematic sunset lighting."
Alex thought, "No problem. I'll use V-Ray Light Gen. Click a preset. Done."
They selected the dome, chose "Sunset," and hit . vray light gen not working
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.
Panic.
They restarted 3ds Max. Reset the scene. Tried "Morning." Same thing. The dome light stayed stubbornly black.
Alex’s Windows username was — with a space. It was 2 AM
The fix? Change the to a simple path like C:\VRayTemp (no spaces). Or, in newer versions, update to the latest hotfix.