unknown error (4000)
Hello,
I can't installing my update, the massege appears :
unknown error occurred (4000).
I tried every single step, but still occurred.
Thank you
iPhone 7, iOS 15
Question marked as
See this Apple article: If you see an error when you update or restore your iPhone, iPad, or iPod
If you see an error when you update or restore your iPhone, iPad, or iPod - Apple Support (SG)
Guess you use a Windows PC, if so check all the AV & Firewall you use on the PC.
Disable all AV & Firewalls temporarily while you restore & update your apple device.
If they are On, turn Off Hotspot & VPN.