Have exactly the same problem. When trying to upgrade to 27.1, system said loading software and then went blank. Left alone for ages but no joy. Evetually managed to get the disk out thanks to tips on this forum, but with a slight change as follows- 2002 BMW MKIII- when I hold in the eject button the light does not go out, but after about 2 minutes the disk stops turning. When you release the eject button at this point the light goes out and when you press again the disk ejects.
Question: I have tried 22.1 as suggested here, but have had only succeeded in frustrating myself. As I now have the 'simple' screen with only the computer and television showing- do you have to be in a specific screen to load the new software. I have tried various combinations ie. from set screen and diagnostics but no luck.

Hoping for some help before I trot of to the dealer as I don't have the original software. I am not sure as well that the disks I am making are good or that the system is now trashed. Will try the battery disconnect when I get home.