Strange sun problem

[Stirling]

Using VRay 5 hot fix 2 and am having a strange problem with one scene. Also using Max 2021, though am potentially switching back to 2020 due to the endless problems I have with it and a loss of performance in the viewport, but that's another issue.

I have a simple daylight system and VRay Sky in the environment override slot but the sun will not light the scene even though it says it's active. Weird thing is if I start IPR there's no sunlight but if I hide the sun or the layer that it's in then suddenly the sun is active again. If I start the render again, same thing happens and production has no sunlight at all.

This doesn't happen in any other scene and have tried to merge everything into a new file with the same result. Also removed the sun and set up a new daylight system, same story.

Any ideas what could be happening? I'm stumped.

[hermit.crab]

Could you send the scene via the contact form so we can take a look? Mention this thread in the message.

[Stirling]

Thanks for the response. I've just gone through the process of merging parts of the scene one by one into a Max 2020 scene and it seems to be working ok. Will follow up if it happens again but I suspect it's nothing to do with VRay and is just another glitch in Max.