What is becoming apparent is that the update was not tested on a MacBook Pro. Because the update fails with an error when sending an ATA command “DOWNLOAD MICROCODE” to the drive. There have been many reports of sucess using a Windows machine though which makes me wonder about which machine was actually used to test the update.
To check the error code:
when the menu appears enter “e”, then “e” again to edit the command line. The serial number can be changed as well as the debug mode. Afterwards “enter” followed by “b” (boot) will continue the boot process. Use at your own risk!!
