@fchody
If the low level format finishes successfully, reboot it and then try again to copy the V6 basemap over to .System folder. Reboot again and if it's still there connect again to GE to see what happens. If it still won't update fw and maps etc., we know it reads from sd card, we can also try to update fw BINs from sd and use txt command to attempt writing files to rgn83 where the visible file system is stored. We're not finished yet.

@asprin264
I've seen this previously with a few Garmin devices, it's not an everyday occurrence though. This type of problem is quite common with cheap USB sticks, some can be recovered and some can't. I have an entry-level price 8GB Lexar on my desk which won't accept new files or allow deletion of existing one which i need to try but it's only worth ~$3 so no big loss.