I am trying to update my phone via iTunes to ios14 and I keep getting this unknown error (4000)
currently on 13.6.1 iphone 11 pro
iPhone 11 Pro
Error 4000 is an undocumented error code (at least publicly undocumented). It means that the connection between the phone and iTunes was interrupted in the middle of a sync or update activity. In the past this might have been caused by a flakey USB port, an antivirus or a firewall. However, there is a new cause of this error that is the result of a bug in iTunes for Windows that requires the phone not be locked during the update. So first check your antivirus and firewall (temporarily disable them), but if that doesn’t fix it there are three workarounds for the bug:
Note that this error should only be a problem for updates; if you are restoring iOS rather than updating it should not occur.
iPhone12 Mini - Same issue updating to 14.2, tried everything.
Removing passcode works. Thank you.
Kilgore87 wrote:
Any idea when we can expect Apple to fix this problem?
No idea. A number of us with connections to higher-ups within Apple have been unable to get an answer.
You do know that once the update downloads you will be prompted to enter the password to install it? If you don’t respond to that prompt the update will fail.
lol fine, to be perfectly clear, the update would fail even after entering the password correctly.
that’s why removing the password apparently works. Happy now :)
Error 4000 occured when I was trying to update to v14.3... And switching off passcode worked. But why is this the case? is it an IOS bug?
It’s a bug, but it’s an iTunes for Windows bug, not an iOS bug. If you can downgrade iTunes to 12.8 that’s a workaround.
iOS14 Error 4000
