Revit Rendering Mysteries - Give a virtual dollar to whomever can solve this debacle!

[cellador82422912]

Ok here is the initial (cloud) render, fine and good.
Playroom Romper.jpg
Next we tried to render the same view at a later date, and this...
Playroom 1_Cloud.jpg
This was then fixed by loading the file on a different machine on the network and re-rendering on the cloud. However, somewhere along the way this happened...
Screenshot_3.jpg
and this happened on multiple views set up in the same room.
However, these same lights from the same family work just fine in another room.

These are all cloud renders. Why they have rendered fine in the past but no longer will render here is beyond me. It makes me angry!
I suspect somewhere along the lines the default light material appearance properties may have been tampered with, but that is my only guess.

[rbcameron1]

Your guess is partially correct. The light source has been adjusted in such a way that it will read the source as a "panel". For instance, look what the cloud did to my Can Lights for a ceiling. (see attached) Funny how it renders perfect on my computer, but the cloud renders it as a giant 15" diameter UFO lighted disc.
The solution is to find lights in your scene that are ON and NOT creating panels for themselves while rendered on the cloud. Reverse engineer how one of the good light fixture families is set up (light source definition, direction, etc...) and match settings on the lights that aren't. It eventually worked for me as a fix, but each family type was different.