Did you by chance use your USB in a Mac before attempting the upgrade or was it a Mac formatted USB? I've seen some issues there (probably related to all the extra little files Apple writes in if I had to guess), as well as when Mac changes the file suffix rendering it useless until it is renamed properly.
Did you by chance use your USB in a Mac before attempting the upgrade or was it a Mac formatted USB? I've seen some issues there (probably related to all the extra little files Apple writes in if I had to guess), as well as when Mac changes the file suffix rendering it useless until it is renamed properly.
