I've been trying to update for about 30 minutes. I got error "21" initially. Then iTunes said I had to restore the phone, but iTunes keeps crashing during the process. Luckily, I backed up the phone on iTunes and iCloud before any of this!
Second time around, now, and iTunes says "Preparing iPhone for restore..." and it's taking forever. I need to get going soon, ya know?!
OK, now iTunes doesn't show the phone in the sidebar and the program is frozen (2nd time this has happened). The little iTunes icon in the Mac's dock is jumping around like hell. I'm guessing if I force quit iTunes, the process will start all over again...again. Here we go, let's see what happens.....Yup, after restarting iTunes, I get this message:
"iTunes has detected an iPhone in recovery mode. You must restore this iPhone before it can be used with iTunes." OK, but how about letting me do that!!
Any suggestions out there! Help!
EDIT: OK, so I clicked on the error message ("More information") and Apple suggested deleting the ".ipsw" file and trying again, among other things. This seems to have worked as the phone is now being restored.
But it's still 90 minutes of my day I couldn't afford to lose. Sheesh!