That iso file directs it to the other folders to pull the updates. I'm having the same issue as you clear down to the re-insert usb message. Reformatted the usb, uploaded 1.19.1.1 again to restore the radio to functioning. Cleared the usb, put the footprint back on it so Naviextras would see it. Downloading the map updates to the usb this time instead of to the PC and then copying it to the usb. Hoping for better luck this time around. Going to be a few hours before I have it from the website onto the bike to check if it worked.
I selected the map update from the NaviExtras this time. The USB auto-updated when the software found it so I have the swdl.iso on the USB, but I am downloading the map update which is taking some time. I will see what kind of file that generates when the download is done.
The adventure continues......
UPDATE----with map update on the USB key(in the NaviSync folder) AND the swdl.iso file, the radio found it and is applying the 1 of 1 NAV update. Now let's hope it finishes.