I re-installed 2.0.3 over the top of itself and it ran fine. Running Tools gave me some DB disparities which I fixed using the supplied link.
Then I installed the updates to my add-ons, ran Tools again, fixed the Add-on issues with the supplied link and CB looks OK. All Tools show green
I still have a problem with CB Subs GPL 4.0 but that is for another forum.
Thank you for your help - it's never easy to know when re-installing is the answer.