You'll have to forgive me if you answered all this elsewhere - but I can't recall or remember now what the original problem was as this has got scattered all over the forum

- but if you have topped up the adblue tank and are still getting this warning, then I would use those 200 miles to get it to your nearest Citroen dealer and let them deal with it at this stage - otherwise you are going to have to fork out for towing on top of anything else if it gets to that stage.
There is no guarantee you are going to be able to do anything with Diagbox in this state and it was always a possibility that you may need a later software version. But the interface issues on top of everything else are just compounding the issue. I would cut your losses, get the car to the dealer, let them diagnose and sort out the De NOx issue / or worse the adblue tank. I'd then start a return for the VCI kit you bought and send it off on a slow boat to China and tell them it's faulty.
Things are going nowhere fast at this juncture and time (or miles in this case) are running out. I don't want to sound negative, but there are so many factors at play here, it's becoming difficult to focus - and I'm sure you're going crazy.
