Cubase 9 Win 7 VST mapping

Hi
I have a Windows 7 PC running Cubase 9. I have been working on a track yesterday and this morning without any issues. I just popped out to fetch someone…got back and when I open the track in Cubase, it tells me that it cannot map Omnisphere or Kick 2 X 64. All other instruments are fine. I have tried re-installing and checked the vst manager mapping, but still no luck. Both instruments are in the loading bay, just won’t load into the track…or even a new project, for that matter.
Has anyone had a similar experience, perhaps?
Cheers,d.