Any help gratefully accepted.
Have experienced the same problem with a 2012 RT, bike failed to start. We were in Germany, a Sunday overnight stay was arranged, before the recovery guy turned up the next morning. Tried the bike early on Monday morning and it started, rode to Kassel and had the switch changed.
Try and drive out any moisture from the switch and/or use some electrical contact cleaner, might just work.
If the bike was purchased less than a year ago from a BMW dealer, it should have a 1 or 2 year used bike warranty.