iPhone XR - Error 4000 when trying to install iOS14 over iOS 13.7

Same issue here with error 4000 - latest iTunes version, whether iTunes

from Apple or through the Windows Store - iPhone 11 Pro Max and iPad 6th

Gen. This has been happening for the past few update cycles. I believe

the problem lies in iTunes thinking the phone/iPad is locked, even if

you keep the screen on and enter your unlock code when asked. The only

way I have found to update using iTunes is to turn Passcode off in

settings, then it will update. Only thing is it will delete and

debit/credit cards in Wallet and you have to re-enter them. Apple really

needs to fix this.

Thanks. I may have fixed it. I removed the lock, that is removed my passcode on my phone. It ran for a long time but updated because everything looks different. Thank you for the reply. Now i have to remember to put my passcode back on.

Yes, this problem still exists. Only removing deactivating passcode helps.

If you have Apple Wallet then your cards will be removed. You can add them back after updating.

Remove / deactivate passcode, then you will be able to install the update.

Frustrating that iOS requires you to remove all your Apple Pay cards though when removing passcode (although a good security measure).

This shouldn't have to be the case, wasn't an issue for iOS13.

>> I have to go with OTA then again as I cannot disable Passcode...

Yup, that’s what I did. Note that you probably will get a verification error the first time, just tap retry and it worked for me.

I can’t say, I have not had any issues with syncing, only updating iOS or iPadOS via iTunes. I get the error 4000 even though I enter the passcode when requested. Only way it completes is disabling the passcode.

Try to deactivate the passcode before updating. It solved the problem for me.

Deactivating passcode worked, cheers !!!!

Do you have a passcode on your device? Try turning it off temporarily and update your device? Several people had it work for them. It did for me.

Same here. What I noticed is after backing up, the device goes away so that the install fails with (4000). I suspect if I removed the password or kept the device unlocked it would work but didn't have time to play with it, I did the update from the iPhone. Had one glitch the first time where the update wouldn't verify but that could be due to busy servers. The second time, it worked fine without redownloading.

Thanks it work for me

tried before with 3 pc same result etreur 4000

where are the guys from apple? It was simple to say put off your passcode before update

congratulations to the comunity to try to solve our problems

best regards from portugal

Guess you found it in this thread 😉

https://discussions.apple.com/thread/251803333?answerId=253458274022#253458274022

This worked for me, I also deactivated a work email account too

How is this considered solved when the point of the OP was to perform the update via iTunes on a Windows PC? I’ve wasted hours myself across two different computers all with the same exact failure. Evidently Apple didn’t think it was necessary or important to properly test this upgrade path. Super frustrating!

just a status update: I updated everything (Windows to 20H2, iTunes to 12.10.10.2), downloaded the 14.1 FW and made a beckup beforehand, I tried to update my iPad mini 5th gen from 14.0 to 14.1 -> still Error 4000

I have to go with OTA then again as I cannot disable Passcode...