821 2015 one year old 6k miles; left side centre stand bolt came out. Noticed it 2 days ago, came back from a ride and was putting the bike up onto its centre stand and something didn't feel right. Looked down bolt gone. Had ridden bike two days previous so it must happened on my last ride.
Phoned dealer who had one in stock, which made me suspicious;-) since this dealer has very little in stock. So might be a more common problem; dealer very apologetic and didn't even think about asking for money.
I'll be checking them regularly from now on since as said this failure could result in a big big accident.
Follow on. Getting stand back on was a right PITA until after phoning round a few shops looking for a 'suitable' spring puller ie substantial, a mechanic told me to use a strap ratchet between the stand and a spoke on rear wheel to pull the stand into place so I could get the bolts in. Worked a treat. I had previously tried this, fitting the spring on the free stand and then trying unsuccessfully to manoeuvre it into place manually.