Hi everybody,
I also have the same problem with that missing items in few recent projects. From what I heard, it looks like because of the GROUP/ COMPONENT issues. The fact after having some annoying of missing material layers, IES lighting data, I tried the most common way using copy/paste to a new plain file. So when I hit render with a new file, it turn out with nothing but the background !! Then I select all and put into GROUP. Wow..Objects got back in render frame again but material layers and lighting data still missing. So strange..Somehow it'a last solace than nothing !!
