I had the same problem. But on the third try it updated successfully. For my case, I waited for a few minutes in order for the download to start. Maybe it was due to server speed.
The panel look dead if update unsuccessfully. Only have a dim red light blinking on the top left (near USB port)
Almost had a heart attack at that time because I only received the Throttle for a few days.
Ps. How to join Winwing Discord?