If you can get ista-p which programs modules, you might be able to recover the FRM. I had a success with a friend's e70. Supposedly the old software has a bug that messes up the initialization at first start (like after a full drain).

I used a generic eBay k+dcan USB cable with my laptop.
Battery charger while updating software is essential. If it has 2 settings, like low and high, use the high setting because these BMWs love to guzzle electricity when the engine is off.