[Maya] to [Unity] Tiled Mesh, Lighting Problem At Connection Points

RawData

Hello everybody, i prepared bunch of parts to create modular environment. I set the scene in Maya and send to unity to test. I put one directional light as Sun and put point lights to windows. All of them are real time. Every mesh intracts with the light individually and that causes the problem below. I know a lot of people create modular scenes of course. How can i solve this? I searched on web but couldnt find something fixes my problem. Thank you. 

RawData

So what i found till now, after read tons of forums,blogs, tutorials, if you dont want those seems you have to combine them. The other tweaks you do just help to reduce it but cant totally fix. Also deferred rendering helps but idk. If anybody gives advice i appreciate.

RawData

Nobody? Really ???

stilobique

I don't know Unity, it's a static light (with a lightmap build) or only dynamic light ?
With Unreal, this error can be a bad UV lightmap or an bad light setup.