It read...
"Front parking aid sensor view restricted due to surroundings.No obstacle detection"
It was sometimes followed by a graphic with a hand and a wet sponge, suggesting the sensors required cleaning.
Everything was clean and appeared to be in order. So I booked it in to be checked over and the dealer said one of the front sensors had a stone chip and would need replacing. They sent a video of the chip. Given that the unit is about 15mm in diameter, the stone chip was probably about 2mm and just visible.
The invoice for this to be replaced was over £400

After 'negotiation' and 'good will gestures' etc. the price was reduced to £220, but this is still astronomical.
I've attached photos in case other owners experience the same thing. Just for a laugh, look closely at the photo of the damaged sensor itself and see the size of the scratch, lighter grey to the right of centre. £400+? Really?
So next time you see a stone coming towards you, take carefully planned evasive action. It would be cheaper to replace the windscreen, I reckon.