I ran in to this same issue, created an account here to post my resolution.
I have a regular ARC. I like this thing because it is dead simple and has an enormous battery. Im sure there are other ereaders that are good too, but i'm happy with this one. It has been running a bit sluggish, so I decided to do a factory reset. BIG MISTAKE!! Turns out I needed to update the darn thing before doing that. I work in software testing so I ca understand the developers' needs to update their software to match latest security standards, but two emails in my inbox wasn't enough notification for me to follow the instructions. I guess I should pay more attention to my email.
I factory reset the device and got stuck at the update screen, error #7. This is where the run-around began. I found the help article at the kobo website (
https://help.kobo.com/hc/en-us/artic...o-Arc-software) but I didnt pick the right model number.
When I tried to install the update for the arc 7 the device wouldn't take it. also, when copying it to the device I would get no progress bar. so both of these things led me to believe that the device was bricked.
the solution in my case was two non-intuitive pieces of information
1. use the software for the regular arc, not the arc 7.
2. even though the progress bar is not udpating as it would with any other file transfer, the update did eventually end up on the device. it took about 5 minutes but it was on there. afterwards I disconnected and rebooted, and the update installed.
Also, I wasn't able to see the device on my mac computer since i believe one needs to enable the usb file transfer option in the settings, but since I had reset my device I couldnt access the settings menu. It only worked on my windows 7 computer.
I hope this is helpful for anyone experiencing this!