Issue with overlapping lightmaps

Hello! I’m working on a project that is not accepting any new model, every object that I Import from my modeling program, after building light it says that uvs are overlapping, even if it’s a simple object like a cube… In the ue4 editor I can see that the uvchannels are OK (0 for texture and 1 for light) and the light map is NOT overlapping… I never had this problem before, I know how to unwrap in the right way cause its not the first time I do this. Also the models that I try on my “corrupted” project, are working fine in a new blank project… so I’m a bit confused :S The original project was created with version 4.12 and I updated to 4.13 preview but I doubt that’s the problem…

I also noticed that after adding any new model the program does not show the message in red “Lighting needs to be rebuilt” (I do not know if that has something to do or it’s just because I deactivated any option by mistake…)

I just want to know if this Is a known issue because it’s really frustating for me, it’s an important project and in a future I will need to keep adding new objects :confused:

Thanks in advance.

+1. Because I add my own lightmaps in Blender using the Texture Atlas, I disable ‘generate lightmap’ in the import settings. I never got overlapping UVs in 4.12 doing it this way, but now I’m getting 96+% overlapping UVs in 4.13.