I downloaded the updater v2.6.11.0_r1.
I ran it, and the program window text is mostly not English. The layout of the window matches the screenshots that are posted on the STEP-BY STEP-PROCESS at
Razer BlackShark V2 Pro (2023) Firmware Updater | RZ04-0453
The first window, when I click on the button that should be “NEXT”, closes and a new window opens that matches the second on the step-by-step page, except again not English.
The part of this window that should be the prompt to plug in the dongle displays the circle with numeral “1” filled in GREEN. I initially supposed that means it has detected the dongle, but if the dongle is not inserted the numeral 1 is still GREEN.
The “Power on your headset” section, circled numeral 2 is grayed out. I assume that means it is not detecting the headset.
The button that should be “CANCEL” does close the window, but the green button that should be “NEXT” does nothing.
I cancelled the updater window, powered off the headset, then removed the dongle. Waited a minute, then opened the updater. Numeral 1 is GREEN. Plugged in dongle, no change. Turned on power to the headset, no change.
Note: I had just updated Synapse to the latest version immediately before attempting the firmware update.