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 temperatureReassembling the frame and the lateral footrests
Apply the recommended grease to the thread of the pins (9) and of the nuts
(8).
Place the frame (1) and the brackets (2) and (3) on the engine block. Start the
pins (9) by holding the nuts (8) and insert
without tightening the screws (6) into the adjusters (4).
Position and fix the rear s ...
Disassembly of the generator cover
Undo the three stator retaining screws (25) and the two retaining screws (9)
of the two cable grommet bracket (10) from
inside the generator cover.
Remove the stator (2) and the cable grommet bracket (10).
The generator-side crankcase cover is fitted with a bearing (27), held in
pla ...
Refitting the intake manifold and coolant union
Apply prescribed threadlocker to the fitting (12), start it with seal (24)
and tighten it to a torque of 2.5 Nm (min. 2 Nm -
max. 3 Nm) (sect. 3 - 3, Frame torque settings).
Install the pipe (b) and tighten the clamp (a) to the torque of 1 nm +/- 10%
(sect. 3 - 3, Engine torque settings).
...