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unknown error occurred (4000) during update to IOS 14.1

What does a 4000 error mean on an upgrade?


iPhone XR, iOS 13

Posted on Oct 20, 2020 12:37 PM

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Question marked as Top-ranking reply

Posted on Oct 26, 2020 8:46 AM

Error 4000 means that the connection between iTunes and the phone was interrupted. Typically this meant that an antivirus or firewall was blocking the connection. However, there is also a bug in iTunes for Windows v 12.10.9 and 12.10.10 that won’t connect to a screen-locked phone. The only current workaround is to temporarily disable your lock passcode before updating with your computer.


The alternative is to update over the air by going to Settings/General/Software Update.

4 replies
Question marked as Top-ranking reply

Oct 26, 2020 8:46 AM in response to datsgir

Error 4000 means that the connection between iTunes and the phone was interrupted. Typically this meant that an antivirus or firewall was blocking the connection. However, there is also a bug in iTunes for Windows v 12.10.9 and 12.10.10 that won’t connect to a screen-locked phone. The only current workaround is to temporarily disable your lock passcode before updating with your computer.


The alternative is to update over the air by going to Settings/General/Software Update.

Oct 26, 2020 8:42 AM in response to datsgir

Hello Datsgir,


It seems like you are getting an error when attempting to update your iPhone. We understand how inconvenient this can be and we are here to help.


We have an article that you may find helpful with this issue: If you see an error when you update or restore your iPhone, iPad, or iPod


If you are still having issues, we would recommend accessing: iOS update and restore errors


If you are still having issues, can you provide more details about what you are experencing? Which device and current iOS version are you currently using? Which computer and OS are you using to update? Also, what happens when you attempt to update over-the-air?


Cheers!

unknown error occurred (4000) during update to IOS 14.1

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