I am guessing these are all using after market bulbs. German makes use specific bulbs with pre-specified resistance measurement. I purchased a bulk pack 2 years back of cheapo brake light bulbs, but the bulbs kept giving errors in iDrive every day, as well as blowing pretty frequently. Someone wiser told me to change to OEM bulbs (OSRAM if I am not wrong), and the errors stopped immediately.
So far, I have had to replace just one brake bulb in a year's time. I had placed LED SMDs in place of my reverse bulbs, and then started receiving errors everytime I put my car in reverse. Fortunately, I learnt that I can disable the error checking of specific bulbs, and it wont get picked up or reported by iDrive anymore. If I ever go back to normal bulbs, I can always reverse this.
Another bulb (rear right turn) is giving me headaches currently. I am still diagnosing the issue, but it seems an electric wire or connection may be on its way out, which causes the bulb to stop working sometimes and throw errors in the screen too.