Plug-ins won't load

I have upgraded from Cubase 8.5 to 9. In Cubase 9 when I try to insert a plug-in to an empty slot it just turns brown and a small circle with a diagonal line appears. The same happens with the sends. Anyone any ideas.
I have attached a jpeg.
It basically means I can’t use Cubase 9 at the moment. 8.5 works fine.
Windows 10, 8 GB ram.
plug-ins.jpg