Lighting Issue - Weird Line Between Walls

When I build the lighting I get this weird line between my walls. How can I fix this?

Hi!

One solution is not to use modular pieces for the wall but use 1 mesh instead.
The other is changing your lightmass settings to: Static Lighting Level Scale to 0.1 - 0.15 and Indirect Lighting Smoothness to 0.6 - 0.65

That seems to do the trick! Thanks alot