Can not update 5.1.1 to 6.0 on factory unlocked iPhone 4S - An unknown error occurred (-1) (21)
HI all,
for the first time, one of my Apple products is making me mad.
1.) I have an factory unlocked iPhone 4S running 5.1.1
2.) When I try to update, it (MacBook Pro running 10.8.1) extracts the software and then after a few seconds it shows me (An unknown error occurred (-1))
3.) When I put the phone in DFU Mode and try to update it shows me (An unkown error occurred (21)) - The iPhone freezes at the Apple Logo
I have downloaded the IPSW again (Yes I am sure I have the one for iPhone 4S), have downloaded and installed iTunes 10.7. Further I have installed iTunes fresh on a another Laptop (iTunes 10.7 on Windows 7) - Same behavior there.
The funny thing is, when I restore the iPhone to 5.1.1 it restores it without any problem. I have also tried to first make a restore on 5.1.1 and directly on 6.0. Same problem.
PLEASE HELP ME!
Cheers
Peter
iPhone 4S, iOS 5.1.1