[Solved] - No sound from artist

I have recently upgraded to Artist from Sonar X1 Essential. I have loaded the Garritan/Aria VST.
Have assigned piano to track 1 but get no sound when playing the virtual keyboard in the Aria VST but the meters show activity.  I can play mp3 files and also my DAB tuner via the audio inputs.
 
I am obviously missing something simple but it is many years since I setup the earlier version (which still runs fine.)
Any help would be much appreciated
 
Martin Lord
 
 
 edit: added [solved] - sc
 

Thanks for circling back.
In the future please edit the original post when a solution is found and add [Solved] to the subject line.