The activation of this (amber yellow) "warning" indicates that the hands free system has detected that the battery that permits the active key (1, fig. 62) To communicate and turn the vehicle on is almost discharged.
Note
In this case, ducati recommends replacing the battery as soon as possible as described in the paragraph "replacing the active key battery" (page 88).

Hands free key (hf) not recognised
High engine coolant temperatureHow to start the engine
With the motorcycle off and the dashboard on, the on/off switch is turned to
"run off"
With the motorcycle and dashboard on, the on/off switch is turned to "run
off".
To start the engine, simply push the on/off switch up to "run on" and press the
black start button.
...
Checking the fuses
The main fuse box (1) and the secondary one (2) are located in the tool tray;
to reach the fuse box remove the seat as
specified under sect. 5 - 3 "Removal of the seat".
The fuses are accessed by removing the cover, which shows the ampere ratings and
mounting locations.
For ampere ratings ...
Throttle twistgrip
Upper clamp
Counterweight
Screw
Handlebar
Grips
Throttle twistgrip
Bush
Screw
Bush
Throttle cables
Spare parts catalogue
Diavel abs handlebar and controls
Diavel carbon
abs
handlebar and controls
Important
Bold reference numbers in this section identify parts not sh ...