Thanks Tig,
I thought i was being clever removing V-Ray as I'm pretty sure that was the cause of all the problems I was having.
Anyway I decided to cut my losses and totally uninstall and re-install sketchup. Followed all the instructions as per the sketchup website.
on opening the new install of sketchup, still got the error message as above but weirdly also had scatter and podium still showing in the plugins dropdown. I thought by uninstalling it would remove everything and i can just start again with a fresh copy. what should I do? any ideas.