Yes, thanks stevef,
I eventually got to realise the problem was wine, but the issue seems to have been a bit deeper, and involved the update process not being able to open a locked file.
Under sudo I tried apt --fix-broken install, but got permission denied. I even tried root but still had problems.
Meanwhile, I tried to update my VPN but the .deb installer refused, saying the system fault had to be solved first.
Long story short, I eventually solved it under root, and initially hadn't realised how many separate parts (packages) to wine there were.
But finally solved it by using under root (sudo su) with:-
apt remove wine*
apt autoremove
Got a bit worried with all the auto removals, especially when it said it had detected my dual boot, since I now have both LL4.8 and LL6.4, as insurance.
But all was well, and it obviously had a very good clean up, as I hadn't used autoremove since installing the system.
All I have to do now is work out the best way to install the latest version of a stable wine.
Many Thanks