[j_petrucci]

are you talking about that yellow stripe? if you are using Maxwell within Cinema 4D plugin, it assigns that yellow material as a default for new objects, so you should check if that's case, keeping in mind that Maxwell tags propagation doesn't always work as expected...

[Renato Lemus]

check your emmiters geometry and the normals of walls and roof. seems like the floor is self-iluminated, or you have a lost emmiter near there.