I had this issue (firmware 8.2) on the road when changing up from 1st to 2nd at / near rev limiter RPM on bumpy ground which induces axle tramping / wheelspin - it's actually a gearbox sensor detecting the over-rev rather than an engine over-rev. I had to completely power of the car to reset the error. I reported it to McLaren B'ham who were aware of the issue - To be honest I'd hoped it would have been sorted by now as not only is it embarrassing but it's potentially dangerous to lose almost all power when you need it most!