I started getting the message "ME is in recovery mode" when booting. Followed these instructions to update the BIOS.
Now I've waited several hours and nothing is happening.
"Updating your system's firmware. Do not power down you system". Also "Flash progress" is at 0% and the message below states it's "Sending Intel(R) Management Engine FW Update".
I have win7pro running on the machine, if that bit of information helps.
I'm in this situation with a E6420. Trying to update the bios from A14 to A23, the system remained blocked at the second pass, with the progress bar at 0%. After about an hour at 0% I powered off the pc removing the cord and the battery. With surprise, the bios has been updated to A23.
In any case the message "ME is in recovery state" is still present.
To resolve the ME problem I've also tried to flash the bios to an older version, the A12; also in this case the pc hung at 0% at second pass, turned off and updated succesfully. The ME message stiil present.
Now I'm thinking to attempt a further update to A12 leaving the pc running for more time, with the hope that also the second pass, if this second pass is related to the ME firmware, ends well.
I'll keep you updated.
Important: do not attempt to turn off the pc during bios updating operations. I'm been lucky but I don't know what can happen to you.