I’m having a weird problem which I don’t remember I have before (with corona renderer)
As you can see, I imported a sketchup model, then I used light material for lighting, both light and ceiling in there are flat surfaces but there are some “stains”.
I can’t think of any good reason for that, any clue?
What is your Unit Setup and how far away from the 3dsMax origin are you?
Might me related to accuracy, not exactly a light leak, but still worth a shot.
units are cm, my model was away from origin (easier to update and import something right into a specific place), so I moved to origin and tried a draft render, same result.
This is fixed in Corona 1.5 hotfix 2. Pressing “reset settings” in scene setup is however required for older scenes which were saved with incorrect settings (e.g. UHD Cache precision set to 0,4 - manually changing precision to 1.0 is not enough!).