Hi, I'm an idiot!
I thought the update was quick and did it with a battery! I know...and I hate myself.
Of course, the update take a long time and the battery died during the process.
Now when turning the pocket 4k on, the screen remain black and the update utility doesn't recognize it anymore. The blue light on the left front is blincking but that's all.
So, I was thinking about maybe a reset of the camera but I can't find anything on the net about how to do it.
Any help? Even for a fool like me?