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 temperatureRemoval of the movable tensioner/timing belt
Loosen the nut (8) and remove the washer (7) and the tensioner pulley (9)
from the pin (12) on the cylinder head.
Remove the timing belt (14) from the horizontal cylinder assembly.
Important
If the belts are to be re-used, mark the direction of rotation with an
arrow and also mark the cylin ...
Removal of the fuel tank
On the usa version remove the canister filter as indicated in sect. 8 - 10,
"Removal of the evaporative emissions
canister".
Loosen and remove the front retaining screw (4)
Remove the flange cover (a) by loosening the screws (b), disconnect the
quick-release fittings (c) from the fl ...
Recharging the battery
Examine the label on the battery showing the check intervals in order to
determine when to test the voltage.
Charge the battery if the open circuit voltage is lower than 12.8 V. Leaving
the battery discharged for more than one
month could damage it. Check the battery charge with a voltmete ...