2012 Mk VI 1.6 tdi Match BMT - Suddenly will not start

[bondaneka]

Car is regularly serviced and has just reached 50k miles. Was working fine - with the exception of the STOP/START function which has worked only twice in the last 8 months - until I tried to start it yesterday afternoon. On switching on the ignition, a beeping sound is heard, the steering wheel and brake warning lights come on, the engine starts very briefly, immediately stops and then tries to re-start unsuccessfully. The beeping sound continues throughout and the messages "Button for driver assistance sys. faulty.", "Oil pressure: Engine off! Owner's manual!" and "Error: Brakes. Workshop!" appear in that order until the ignition is switched off when the beeping stops. I thought the problem might be a dead battery in need of replacement (its decline seemingly likely to be the reason why the START/STOP had stopped working) but I had no joy trying to jump start it. I wonder if anyone could suggest an explanation for this sudden failure? Many thanks.

[bondaneka]

It gets worse. I fitted a new battery to see if that would fix the problem - it didn't but fine as the car is booked in to a local VW specialist in 4 day's time and a friend has offered to give me a tow to the garage. So today I thought I would give the car a good clean. All the electrics, save for the radio which was asking for a code which I apparently have to go to the main dealer to have input (I have never had it, despite owning the car from new but I assume this is the norm in the UK) seemed to be working fine so I dropped the windows to clean their seals - and guess what, they won't close. Rain is forecast so I have had to resort to plastic sheets and sticky tape as well as disconnecting the battery to reduce the risk of the alarm going off.

[Crasher]

New battery or not it would seem to be flat!