Alright, now this is just getting beyond a joke, as you can see by the attached image, there is a volume object where there shouldn't be one!
There is a volume cloud in the animation but only at the beginning of the sequence and it is applied to another object, not the one selected. I have coloured the volume object to make the problem more visible, it would appear that somehow the volume is being projected on to all nulls in the scene. This is obviously a very serious issue.