My Phantom 3 Professional was last successfully flown on Wednesday, 18 Jul '18 with my Apple iPhone 6s and the DJI Go app.
Today I wanted to fly it again and the phone screen kept saying Aircraft Disconnected. I tried everything to no avail.
Out of pure frustration I cleared the app cache and uninstalled the DJI Go app, restarted my iPhone and reinstalled DJI Go app again.
Now the app does not even read the transmitter/remote.
The app starts up but no model is detected. Both transmitter and Drone switched on. IPhone connected with same lightning cable used on Wednesday, to transmitter.
If I am not mistaken iOS had an update to version 11.4.1 on Thursday, 19 Jul '18. Could this version not be compatible with DJI Go?
Any suggestions?
It seems that the iPhone / DJI Go App is not communicating with the transmitter. I have also installed DJI Go App on another Apple iPhone 8 - same thing. No device detected. Transmitter & Drone & App on. Transmitter and phone connected via lightning cable used on Wednesday. I also tried another/different lighting cable to no avail.

Twitter cables and two iPhones - same result - DJI Go app does not detect drone. Needless to say I can't fly my drone...
It seems that the transmitter and the app/phone can't connect.

Sorry - two cables and two iPhones - same result.

Hi, thanks for reaching DJI Forum. We do apologize for having troubles connecting your aircraft using your mobile devices. Have you tried manually re linking the aircraft to the remote controller? For better understanding, please watch the video below and let us know what happens. We're here to help. Thank you.

I have a phantom 3 professional. There is no such button... I did find one as indicated on the attached. Pressing it makes the light red but the remote does not synch by moving the switch. Is there a similar video views the Phantom 3 Professional?

Staffie Posted at 2018-7-21 23:21
I have a phantom 3 professional. There is no such button... I did find one as indicated on the attached. Pressing it makes the light red but the remote does not synch by moving the switch. Is there a similar video views the Phantom 3 Professional?

Button - is thus correct?

Staffie Posted at 2018-7-21 23:23
Button - is thus correct?

Hi there. You may check the location of linking button on your Phantom 3 Professional on your user manual. You may get and download the pdf file manual on our website. Go to the website. Search for Phantom 3 Professional >> click downloads and under that, you will see the manual. For reference, please see the attached image below. Thank you.

Got it sorted thank you

Staffie Posted at 2018-7-23 06:35
Got it sorted thank you

You're welcome. If you have further question, please let us know so can assist you further. Thank you.

Good idea to study, study, the manual.

ALABAMA Posted at 2018-7-23 06:58
Good idea to study, study, the manual.

I bought mine second hand.  Is there maybe a link where I can re-order or download one?

I have the same issue but, first I can't get the wifi network for the RC on my ipad and second when I open the dji app it says hoe to connect on the connecting button..