Problem with lightmass/lightmap?

I apologize for the question, maybe stupid for most of you.
This problem happens while I light a level (internal) with a directional light coming through the window.
(I only use an external light to simulate the sun, also I adding a light spot but the result does not improve)

It seems to me, creating errors in the lighting map, or has problems with the AO.

These are settings that may be interest to understand where I’m wrong:

I tried to check the Overridden Light Map Res from 16 to 1024 (improves slightly but remain artifacts)

set all parameters to ULTRA

light quality to production.

Every tutorial I see on the internet this problem never appears, why on my project?
I tried several times to make a test level again.
Recreating the entire project from 0, but the problem persist, sometimes more sometimes less.

have an idea?

Hi Vanzan,

Please have a look at our Wiki Lighting Troubleshooting and Tips Guide here: A new, community-hosted Unreal Engine Wiki - Announcements - Epic Developer Community Forums

A lot of these issues are discussed here with, hopefully, easy to follow steps on how to correct and look into these issues.

The light leaking is possibly caused by not using a lightmass importance volume or not having properly setup UVs that are snapped to the grid for hard edges.

For the tile seam issue, this isn’t on the Wiki (yet). This is caused by the indirect lighting of your light source. You can reduce this artifact by adjusting the World Settings > Lightmass > Indirect Lighting Quality (2 or higher) and Indirect Lighting Smoothness (~0.6 to 0.75).

Adjusting these settings will not completely get rid of the issue, but it can help smooth it out. Aside from these settings you can try using other meshes to block these edges or import the walls as a single mesh rather than importing smaller wall pieces like this.

I hope this helps.