VSTi's not working. [SOLVED]

Weird problem or idiocy on my part.

None of my VSTi’s are receiving midi.

Example:

Add an Instrument track and select a VSTi. I choose Arturia Pigments. At this point an Instrument track is added to the project with input routing automatically set to ‘All Midi Inputs’ and output routing set to ‘Pigments’.

At this point I believe that if the track is monitored and some midi is played some midi activity should show on the track and some audio should be heard. Unfortunately nothing happens.

Even if I add a separate Midi track and assign it to the Pigments track still nothing is received by the VSTi, although midi activity is visible on the separate midi track.

Any suggestions on how to solve this will be much appreciated.

EDIT: THIS PROBLEM IS NOT PRESENT IN N8 OR N7.

Problem solved with the help of Steinberg’s excellent telephone helpline in Hamburg.

Something to do with corrupted N10 system files.

Had to redo all N10 settings but status quo now restored.