I don't know if it was my post on this forum, or the email I sent to the salesman at the dealership (who is trying to get me to test drive the new Megane E-Tech) but miraculously they managed to get my car into the workshop and found that it "needed several updates, and reprogrammed the BCB and PEB units, removed vehicle lockout and cleared faults". It suggests to me that when the fault that triggered this error has occurred once (something to do with leakage on the Neutral line) the software was not clearing it and preventing you from charging again. For now, I am a happy customer. It just better hadn't happen again!