My brakes went on me about 5 weeks ago, but came back on restart. It sounds like yours are 100% gone though?
Took me 4 weeks of chasing BMW, but finally someone admitted that they've known since June that on bikes made up until a couple of months ago, there's a chance that a spring in the rear brake isn't fully disengaging the brake. If that's the case, the computer will believe that the brake is being applied. Most importantly, this will screw up the start-up routine, disengaging ABS and servos.
After I chased it right up to the Director of Motorrad here in Canada, they finally agreed to replace it on warranty. Not a pleasant experience - lost me a good chunk of my riding season and my confidence in BMW customer service.