Lighting issue

Hello all,

I seem to have a lightmap issue when the light builds, and it seems to only be based upon location. I have a series of halls that are connected. When I build lighting separate they work fine. When I connect them (No overlapping faces) they create very strange and unusual lighting patterns in the lightmaps. Has anyone heard of this before? They have no overlapping faces no lightmap layout issues but when I put the modular system is put together it seems to create very large black areas and incorrect lightmaps.

Thanks for any help.

It’s hard to tell what’s going on without a screenshot

unfortunately due to the nature of the project I can not share any. I can say that I imported them into a new map and built the lighting and there is no error. Is it possible there is some form of hidden geometry or corrupt lightmap that is being deleted?