Yesterday  was "excercise the  batteries on my seldom used Phantom 3 Pro  - which  - including actual garden flights and simulator - has 2hours  28minutes logged as total flight time.   With the radio connected it  flashed up that it needed an  update...so hit the  download - later  hit the "update" there was just a tiny show of blue on the update  track... but after a couple of minutes it reported update complete. I rebooted both the P3 and  TX - but now the radio shows  a red led and4  white..P3 is "Disconnected".    It would seem the TX as lost the "bind"  - OR  could it be something else?   
If it needs  binding again - I have the  process in the manual  - but not sure of any consequence of starting the rebind IF it binding was not the problem.

I have the same issue.  I have re-installed, switched phone and tablet, everything.  Basically wasted an entire afternoon.  My message reads "Remote Controller Signal Weak"

Please try to link RC without DJI GO to check again.

a. Turn on both the aircraft and the controller. Hold C1, C2, and the record button (top left button) on the controller.
b. Then press the wheel on the right side of the controller
c. Use a tool to click the linking button on the aircraft and hold for 2 seconds, and it will link soon.

Matt46 Posted at 2017-9-24 15:49
I have the same issue.  I have re-installed, switched phone and tablet, everything.  Basically wasted an entire afternoon.  My message reads "Remote Controller Signal Weak"

May I know which drone do you refer? What's the current firmware of aircraft and controller?

DJI Susan Posted at 2017-9-25 02:45
May I know which drone do you refer? What's the current firmware of aircraft and controller?

Phantom 3 Professional   v1.11.20
Controller  v1.9.2
Android (Galaxy7 Edge) v3.1.8

Have you tried the re-link procedure? It is not uncommon to have to re-link after an upgrade. One question though. You never mentioned anything about upgrading your aircraft, just your RC. You may have one version on your RC and the older version on your aircraft. You may consider downloading the correct firmware for your aircraft and installing the .bin file on the sd-card and see if you phantom will take it. RC needs to be off while doing this. Just some thing to consider. It appears you haven't flown a lot, so I'm not sure how familiar you may be with the procedure of upgrading. Not to confuse you, but the RC and the aircraft will not communicate if they have different version of firmware on them. You cannot upgrade just one or the other. Now, not saying you did that on purpose, just saying it might have happened. One thing to note too. The firmware package does contain both the firmware for your aircraft and your RC, but within that .bin file is actually 2-pieces of software if you will, and when installed correctly on both, it will show 2-different versions in your app for the RC and aircraft........but they have to be out of the same package. If it shows different versions, doesn't mean they are the correct ones for that firmware version. I hope I haven't confused you. You would think that both the RC and your aircraft should be on the same version, but that is not correct.

mmmm  best selling products in the world...but nobody  around to  advise!!   I just did the re-bind process..ie clicked the button!  Its back to normal now... the info may help others in futire.

Re: #4, #5 and #6

I reinstalled  v3.1.8  DJI GO on my Galaxy 7 Edge and performed re-link procedures which were successful.  My problem is solved.

Matt46 Posted at 2017-9-26 09:22
Re: #4, #5 and #6

I reinstalled  v3.1.8  DJI GO on my Galaxy 7 Edge and performed re-link procedures which were successful.  My problem is solved.

Glad to hear that you have figured it out. Enjoy it and happy flying!

Matt46 Posted at 2017-9-26 09:22
Re: #4, #5 and #6

I reinstalled  v3.1.8  DJI GO on my Galaxy 7 Edge and performed re-link procedures which were successful.  My problem is solved.

Glad to hear! It sucks to be grounded..........LOL
Happy flying.