Not able to pair AirUnit and GroundUnit

I have a HereLink system with the following model numbers:
Ground Unit: HX4-06075
Air Unit: HX4-06074

I am trying to pair them since there was no communication out of the box. In the manual, its been instructed to go to D2D info in QGCS where there should be a display of frequencies received at the ground unit. I see a blank D2D screen. I went through the following topics:

But, unfortunately, none of them seem to be linked to mine. And I could not pair using the standard procedure. Screenshots are as below:
Ground unit D2D screen:

Ground unit system details:
Ground unit pairing fail:

I also successfully upgraded the firmware of both Ground and Air unit and the screens shots are as below. Even after upgrade, I get the same result…
Airmodule update screen 1:

Airmodule update screen 2:
Ground Module update screen 1:
Ground module update screen 2:

Requesting the community to help me out in figuring out what is the issue. Any help or suggestion will be highly appreciated.

@sidbh Most log messages have your name in the path. Could you please help me out ?

Can you share a video showing the process you are following?

Hello @sidbh,
Thank you for the response. Please find attached video link of the process that i am following. Do let me know if i am erring in any way.



Hello @sidbh,

Just checking in. Any help would be highly appreciated.


Try to again update firware with all option selected.
I was facing same problem after update it paired.

please do an update to both the air and ground unit using the latest firmware. Make sure you run the entire update and CLEAR the STORAGE as well. ie “flash_all”. this just ensures the update has no old settings that could cause issues,

documentation is here

Hello @Michael_Oborne,
Thank you for the suggestion. I did the same, but to no avail. Both ground and air unit were on the latest firmwares on the day of raising the issue.

On the air unit what LEDs are on or off and what is the color? Also the controller is not in aircraft mode

Hello @Michael_Oborne,

The air unit LED2 lights up on power on and with steady amber color. When i press the reset switch for 3 secs , it changes to blinking green and stays that way for a minute or so. Since the pairing process is unsuccessful, it changes back to steady amber. LED1 never lights up.

Pairing fails in airplane mode too.