Thanks for the quick response.
What I did was take the standard support engineer approach (the kind you get with many companies) and rebooted
It works fine now, but to answer your question MC5 was working fine (the screenshot) and MC6 looked exactly the same as far as I could see. I did not have MC5 loaded when I first experienced the MC6 issue but because I had loaded various apps and hadn't rebooted for a week I thought I'd make a fresh start. The TD82 drumkit works now too
So I just need to get used to using the software now - that'll have to wait for another day though.