After lots of tinkering and due to the insidious nature of the problem I decided to save what little sanity I have, cut my losses and reinstall.
My DCS has its own dedicated drive.
So I wiped it clean.
Deleted all registry references to ED and DCS
Renamed SavedGames
Reinstalled DCS + Modules
Everything works fine now.
45 years SE tells me some major corruption was going on. Malicious or accidental I don't know.
Salute