I had the same problem when I did the up date. I can not take credit for the fix but I found the answer later after many site visits. I would assume the up-date did not include the need to re-sink your controller to your phantom. To quickly confirm a communication problem, lift the phantom over your head while it is on. You will see a small counter sunk LED light. (This is not the large blinking lights you always see) If the small LED is red then you need to Sync your controller to the phantom. If it is green.... You don't have a sync issue. I had a sync issue after the up-date.
The person I found and followed suggested re-link your RC to your drone. Using the app, touch the signal icon and go down to the picture of the controller (looks like a plug). Now scroll down until you see linking RC. Press this and you will see (are you sure). Hit yes. When it starts to look for your drone it will tell you to touch a button on your drone to send the signal for the controller to find. There is a picture on the location of this button but it does not help much, so basically hold the phantom over your head and you will see a small red (no communication) light up in a recessed area. While the controller is looking ...... Push this small red light (button) in. (Use a tooth pick or something to fit in the hole leading to the light)You will feel it re-set. Let off and let it do its thing. The light will turn green when you are back in communication. Should be a go from here.
