lighting issue / scene completely messed up with flares and spots...

[yotah1]

Hi

I did some renders at lunch with my Bizzarrini scene, as seen below :



As you can see, it's nice and clean, and my overhead light source works just the way I want (btw, that's on Keyshot 4, just in case).

But I saved my scene, and opened it again as I wanted to check out something. I didn't modify anything, and that's how it looks right now :



Renders look the same, switching off my overhad light removes all those awful spots and flares and whatever you can call it, but I need my light source. i tried reducing it's power, removing it, doing a new, changing my materials on the car, nothing fixes it, it's just completely messed up... Problem is, i have to share that with my client in a few hours 

Any idea what that could come from?

[Speedster]

Quick!  Check your "Model Units"!  Edit>Set Model Units.  If "None", try inches or mm.  Play with them.  I ran into this same issue when using IES lighting and some Area Diffuse, and like yours, it did not retain the units when re-opening.  Have not had this problem in 4.2.35.
Bill G

[yotah1]

Indeed, switched it to Meters instead of Millimeters and it worked

Thanks a lot!