Hello.
I would like to answer to this topic because i had the same error codes
The code 0811 - "Bonnet Open or Unlatched", i started my car with open bonnet and got this error once,
The code 0557 - "Rolling Possible, Secure Vehicle", i set "N" position on gearbox and i left from vehicle, didn't use handbrake and didnt switch gearbox to "P" position then i got this error.
I hope this will help anyone who have the same codes, you dont need to worry about anything.. (0811). this is NOT "Excessive Clutch Slippage".
If you want check other BMW error codes i recommend to use this website
https://www.endtuning.com/ccidcodes.html