'Light Transport' job failed with error code: 5 ('Failed writing light transport file.'). What does this error mean?

I am getting this error in my console repeatedly after every sometime. Game runs fine in editor but it won't build. Build process gets stuck on "Light Transport" job. I am a newbie to 3D game development. In face it is my first try in 3D game so I don't know much in detail about the challenges of making 3D games. Any help will be appreciated.