2) ' LightmapCoordinateIndex out of bounds' - I can't find this anywhere. Looking at the documentation it tells me that there are 2 'common' possibilities 1)' lightmap resolution of 0' - if I'm looking in the right place (LODSystem) then it's 256 and not 0. I check the message log and it tells me that the 'Maps need lighting rebuilt.' Okay, rebuild lighting. The issue is that I'm trying to build the lighting, however, when I build the lighting there is an issue and UE4 tells me to check the message log. I was trying to create a lighting example for a proof-of-concept for project, but found myself in a bit of loop. (I posted this on the Unreal Engine forums, but no one has responded, so I thought I would try and post this here to see if someone might have run into this problem as well.)