Cubase 5.5.3 can't load vst 2 plugins

Good to know if anyone can help here - I’ve installed cubase 5.5.3, all looks ok but it doesn’t show my copies of Superior Drummer or Arturia synths. Investigated further and no vst 2 plugins are loaded. If I go to the plugin screen then option to load vst 2 plugins is greyed out so I can’t select it?

I’ve also got a Cubase Essential 5 licence and it works fine there. All licences are valid.

What operating system are you on? Sorry, but I would need to know that to guide you properly on it.