Help! Blocky artefacts from sunlight

[davetwo]

I have a scene wih a directional sunlight (physical sun) on a wall. For some reasoin it is causing square artefacts on the wall (see pic).

I have tried changing the wall geo/phong/materials. Plus changing to solver to 4k/path tracing. Plus copying everything into a new file.  Nothing seems to help.

Any ideas?

[Beanzvision]

Did you try unchecking the adaptive light solver in the performance settings? I recall something like this a while ago and this was the issue. Good luck.

[davetwo]

Just tried turning the adaptive loght solver off - and it has indeed got rid of those  block artefacts!
Thanks Bengamin for the speedy reply - I though I'd seen a similar problem, but couldn't find it on the forum.