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 temperatureReplacing the rear phonic wheel sensor
Disconnect the rear abs sensor (5) connector (c) from the main electric
wiring.
Open all the retainer clamps of the rear abs sensor cable (5): refer to table of
sect. 7 - 6, Flexible wiring/hoses
positioning.
Remove the rear abs sensor (5) from its seat on the rear calliper mounting ...
Removal of the intake manifold and coolant union
Loosen the clips (f) and remove the hoses (t).
Remove the manifolds (25) undoing the screws (21).
Loosen the clamp (a) and remove the hose (b). Remove the union (12) and
recover the seal (24).
...
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 ...