No Sound from VST tracks on elements 11

Sound no longer coming from VST tracks. All used to be OK then suddenly no output sound from the VST tracks. Did a test straight audio track and I/O fine. I can record to the VST tracks with data visibly logged to the track but no monitoring / sound. I have done all the checks I know of but have now run out :).
Any help gratefully received.



Is monitoring activated?


No, tried it with and without, but thanks for reminding me :).