You need to download with Google Chrome instead of Internet Explorer or you will not get the proper file that works.
When you download the file from the ST16 firmware area, you will end up with ( ST16-v3.1.22.yuneec )
If you don't have the word yuneec after the 22 it will not work. So then transfer to your SD card then put in the st16 and proceed to update.
Make sure you format the card Fat32 only takes a second or two in you st16 or computer first before you transfer from your computer.
This was my first Drone but my neighbor has the Phantom 3 and he likes mine better. Says he just might move up to the H Pro later on.
I was into Helicopters years ago and I wrecked more then I flew it seems. This is much better.
Thanks for the tip about Chrome. Also the controller does not like to update from faster cards. This is the same as Moultrie Game Cameras. I live in an area with deer and elk in my back yard a couple of times a week, so I keep a game camera on 24-7.
I think that much of the confusion could have been avoided with a better written manual. Version 1.1 is full of information but it is hidden much of the time.
Only going over it a third time did I find the password and information on Mini SD cards. Much of this should be on an information page and not hidden in the text.