During 3 of the last 5 bootups of my Mavic Pro and Controller, I've seen an ESC error.  The third one was "no3.ESC error", which after a little research, I think means No 3 motor electronic speed control error.
This seems to be an intermittent issue, but I'm not pressing my luck until I find out more info.  Here's an outline of my experience with this error thus far:

I updated the firmware last week in preparation for a flight this weekend.  No issues with the updates.

When I hooked up my iPhone and booted up the controller and drone, I got an ESC error.  Never saw this before.

I restarted the drone, and controller.  Error remained.  Restarted drone, controller, and iPhone and error cleared.  Flew the drone for about 7 mins - no issues.  Landed and shut down the drone and controller.

On second flight, everything connected fine, no issues.  Flew drone for about 15 mins on same battery.  As I was bring the drone down for a landing in what was for all intents and purposes, a wide open field, I was watching the landing through the video camera (and not watching the drone), when it appeared to fall from about 7 meters for no reason.  No obstacles were near it and there was no apparent damage to the drone.  I just packed it up and brought it home.

Tonight I just started the drone up again (indoors on my coffee table) to check everything.  The ESC error appeared again.  "No3.ESC error".  I shut drone, controller, and phone off and restarted each while doing some online research.  Error cleared and everything looks good.  All the rotors "twitched" on startup.  I've shut everything off again while I'm doing more research and posting this.

I'm curious if there's been any correlation between "ESC" errors and IOS or firmware updates? Thoughts?

Hi there, I'm afraid that the performance can not be ensured after the crash. Please kindly start a case and send it in: https://www.dji.com/support Data analysis is recommended to check what happened so that we can offer you a proper solution.