what is error 4000?

Not a helpful response - at least 7 people have reported the same error number (4000) and the same issue here.

Plus, we've all received the following message:

Announcement: Update your iPhone 5 to continue using App Store, iCloud, email, web, and other servicesStarting just before 12:00 a.m. UTC on November 3, 2019, iPhone 5 will require an iOS update to maintain accurate GPS location and to continue to use functions that rely on correct date and time including App Store, iCloud, email, and web browsing. For more information, click here.

So calling it a 'hardware issue' isn't really helpful - it's the precise hardware the update is targetng here.

Is it error 4000 exactly or something like 4005?

Anything here helpful?

https://support.apple.com/en-us/HT204770

It can always be a hardware issue, especially with an older phone.

~Lyssa

Hi! I also had the 4000 error and the warning about "November 3" all the time. And I also couldn't upgrade my old iPhone5 to IOS 10.3.4. But I finally managed by doing that way - Since this was my old phone which I have given to my kid, I had created new iCloud and iTunes user for him. I wanted to update my iPhone 5 with a new (kid's) username. Then I left on the iPhone the new user (kid's) name of iCould but signed into iTunes with my old username. Then I could upgrade to IOS 10.3.4 via iTunes. But anyway - it was not possible to update iPhone to IOS 10.3.4 via WIFI. Sorry for my English, it is not my native language :)

Hope this can help someone :)

i am having a challenge restoring my back up to my Iphone XR from my Iphone 6s Plus.Its asks to update the new phone but it takes 6 hours to download the update and prepare,it then shows an error message ,could not be updated an unknown error occurs (4000).i am really frustrated as this is the second day.

I have the same error trying to update my iPhone 6s Plus from iOS 10.3.3 to 13:1, well now is iOS 13.2. I too have error 4000, not 4005; I see you can click on error 4005 but there is no link for 4000. Hoping someone can help!

I did not say it definitely was a hardware issue. That is just one of many possibilities.

~Lyssa

During update of the IOS for my Iphone 7 I got the error code 4000, what does this mean? I cannot find any clarification for this.

Are you trying to update over-the-air or attached to a computer? What type of computer and what iOS version? Which iTunes version? Have you previously had any camera issues?

Oh and I am updating via latest iTunes on my Fujitsu laptop.