I have read a lot of posts here and didn't find any valid link to download J-Link OB firmware.
Does anyone know where to download this firmware?
FYI for anyone in the future. Just use the J-Link Configurator tool (incl. with J-Link Software and Documentation Pack) to update the firmware of the J-Link OB IC, as shown below. This will ensure that the debug probe running on your host/PC will be compatible with that running on your DK board.