How to solve strange lightning artefacts?

Hi!

You have too few (light) samples in your scene but you set Static Lighting Level Scale low!!
Either set your indirect lighting quality higher (6-8-10) or if it’s a preview light build, set that also higher (medium and above)!

Hi, I have these strange lightning artefacts when baking my lights. I use a combination of movable and stationary light sources. I have a fairly high resolution for my lightmap on the walls (when i check with the light-map density mode it has a red colour). Also my uv-unwrap doesn’t have any overlapping surfaces. Has anyone any idea how to solve this problem?