Objects turn black when building lighting

No idea if this is the best place but nothing else seemed right either.

When I build my lighting, some objects turn black, such as the ATM. The pink one is before building the lighting, the black one is after.

After some googling I’ve found some posts where they say to set the Light Map value for the mesh to 512. And that instantly works to make the object look right…Until I build the lighting again, at which point it goes black again. It actually doesn’t matter what I set that value to, it will instantly look right, but only until I build the lighting.

How do I actually fix this?

Many people have had this problem over the years (some posts go back to 2014) and yet every person who responds to the posts seems to just be guessing at what the problem is. Surely someone out there knows exactly what’s happening here and how to fix it.

Thank you.

Did you check your face normals? They may be reversed and pointing inwards, which could lead to a black surface after light baking.