iOS14 Error 4000

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:

• Update over the air, by going to Settings/General/Software Update
• Downgrade iTunes to version 12.8 if you can find a copy - try https://apple.com/itunes
• Temporarily disable the screen lock passcode on the phone before updating using iTunes on Windows

Note that this error should only be a problem for updates; if you are restoring iOS rather than updating it should not occur.

That’s an interesting link that is far from complete, but I noticed that nowhere does it mention to turn off the passcode.

There are a lot of possible reasons an OTA update will fail. I have tried to catalog all of them here: Updating iOS: common issues and solutions - Apple Community

Fair enough dude, preferably I’d like Apple to fix this error 4000 is and the OTA bugs when installing iOS 14 installation and OTA and bugs.

Nice article by the way :) unfortunately none of it worked for my XS or 12 Pro.

Below is the error message I tweeted to Apple support when iOS 14 came out. It appeared when installing iOS 14 on my old XS. Removing the passcode may not have been necessary, but after doing that I was able to install it OTA. Correlation or causation 🤷🏻‍♂️

Thanks! It helped me too. My company’s device management profile was installed which i had to remove too to successfully update from iOS 14 to iOS 14.0.1.

But, apple should look into this issue. Earlier passcodes need not had to be turned off to update/upgrade.

I am getting an error code 4000 in trying to update my iPad software using a thunderbolt cable from my laptop to my iPad. For some reason there is a bug that is not allowing me to update the software and also causing problems in accessing my cellular on my iPad

Having the same issue now when updating to 14.1.

Bit frustrating this isn't solved yet.

Although removing / adding passcode isn't that much work, having to remove all Apple Pay cards and reinstall them is very annoying

Agreed ! I have also been getting the same issue for both my iPhone X and iPad Pro through PC iTunes update operation. As I do not wish to reinstall Apple Pay cards after disabling the passcode, I updated to iOS 14 and iOS 14.1 through the Settings/General/Software Update menu on each devices. Note that each devices were first backed up on my PC before updating to the new iOS version. I also hope that Apple will fix this lasting bug.

Turning off your passcode momentarily will solve this problem. But my beef is that Apple should've been out front about this and just notify people that this needs to be done prior to installation of the new iOS. I shouldn't have had to google "iOS error 4000" to find out what the heck was happening. This step wasn't necessary for previous updates. Why the change now?

I had the same issue when updating iPhone XS from 13.6.1 to 14.2.

You are fully right - disabling Passcode allowed the update process to move forward and finalize the update with no further headaches.

Aram

Thanks for this. That worked. (Of course, updating over the air also works, but it was really bugging me that I couldn't do it via iTunes.)

I hope Apple squishes this irritating bug soon. I've submitted feedback.

Jenpineapple1 wrote:

Nope. Removing password did not work. I have an appointment to go I. Store to the Genius Bar on Saturday.

After your Genius Bar meeting, would you be so kind to post here the solution, if different from the ones we already suggested?

Thanks and regards

Giulio

Kilgore87 wrote:

Hopefully all of you who have connections can get a positive result.

I've seen this update fail while updating OTA too, so I’d be surprised if Apple’s team weren’t aware

Just curious: did you see that error while updating OTA, or did you read about it?

Thanks

Giulio

When updating OTA, the update would fail. However, after removing the password, the update would proceed as one would expect.

No error number is shown on the iPhone screen, just a message saying “the update has failed” or something similar

Then out of 500 million users, your phone appears to be an exception. Because I have not seen any other posts claiming that the update can only be installed if you remove the passcode. And none of my 4 iOS devices had any problem updating - with the passcodes fully active.

Is that why you’re on a forum that’s specifically discussing installation problems for iOS 14? If no one else was having a problem then I guess this page wouldn’t exist

https://www.howtoisolve.com/software-update-failed-ios-11-on-iphone-ipad/

If you’re not having problems with any of your phones then I’d say you’re fine and there’s more interesting websites to look at. Enjoy your day