Black interior after import from max

Hi im new to unreal and have made a few levels for office interiors . however i have a new project that I’ve imported from max and most of the meshes go black when i rebuild lighting.

i also get poor shadows.

any help is apreciated

UE4 will bake lighting to textures which get mapped to the meshes, this allows you to calculate lighting beforehand and get high quality effects like GI and still have good performance in real-time.
If your mesh turns black or has weird black shading markings after building lighting then it’s likely due to a low lightmap resolution or bad lightmap UV’s or bad UV configuration.

If you haven’t set up your lightmap UV’s then you will need to make a second UV channel where your UV’s fit within the 0-1 space and don’t overlap. When you import the mesh to UE4 make sure to uncheck the “Generate Lightmap UV’s” option otherwise it won’t configure the mesh to use the lightmap UV’s you created.
You can check out more about lightmap UV’s here: Unwrapping UVs for Lightmaps | Unreal Engine Documentation