Identical meshes turn into darkness when i apply (Harvest instances) ?

[Kaydo007]

Hi there

I imported a building from sketchup built up from identical meshes as you can see in the photo, i selected them all and replace them with a single blueprint to save up space, now i want to do (Harvest instances) to convert all my blueprints into ISMs (instanced static meshes), but the probleme is when i do that some of my mesh turn dark, what could be the problem ?

as you can see when i zoom in the darkness fade away, inside the building i have a light source

Thank you all and have a good day

[Kaydo007]

I figured it out, before i harvest the instances some of my meshes were mirrored, that’s why they’re all dark, unfortunately i didn’t find the solution for that so all i have to do is avoid mirroring meshes before harvesting

[Kaydo007]

I found the solutiuon for that is to mirror the mesh 2 times before harvest the instances, for example you mirrored the mesh by X axes, then mirror the same mesh by the Y or the Z axes, then harvest the instances