By Nick / Last Updated February 1, 2021

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iphone update error 4000

I connected iPhone 8 to iTunes and there was an available iOS 14.1 update that had been downloaded. I clicked Update but after a while, it reported: can't update iPhone error 4000. How can I solve the problem and update my iPhone now?

- Question from Apple Community

Apple usually pushes update for iPhone users to introduce new features and fix the bugs in the present iOS.

Updating iPhone is necessary because new iOS often makes iPhone more fluent. However, it is not always easy. The process might fail even if you have downloaded the installation package in iTunes. If you see the error message that The iPhone Could not be Updated. An Unknown Error Occurred (4000), just follow this passage to know why it happens and how to solve it.

Error 4000

Why you can’t update iPhone for error 4000 and how to fix it?

Generally speaking, there could 3 possible reasons for the problem:

◆ iOS has been updated on iPhone.
◆ iPhone screen is locked.
◆ The version of your iTunes is too old.

Now use the following methods to fix the issue.

#1 Charge iPhone before update

If your iPhone is of low battery, to make sure the system is safe, you need to charge your iPhone until there is more than 50% battery.

#2 Check the version of iOS on iPhone

The present iOS on iPhone might be newer than the iOS in iTunes.

You need to go to iPhone Settings > General > About to check the software version.

If you have iOS 12.4.4, you cannot use the update of iOS 12.4.3 in iTunes. However, you would find a way to install old version of iOS in the last section of this passage.

#3 Update iOS on iPhone

Meanwhile, you could check whether there is an available iOS update for iPhone to update iOS on iPhone.

Go to iPhone Settings > General > Software Update.

It is suggested to backup your iPhone before you install the latest iOS because updating iPhone could not only solving the previous problems but also bring new problems.

iOS Software Update

#4 Restart iTunes and iPhone

iTunes error code 4000 could also be caused by simple system glitches. If so, just restart both iTunes and iPhone and then try updating iPhone again. You might find newer iPhone update has been prepared in iTunes.

#5 Keep iTunes up-to-date

Old iTunes could not be used to update iPhone and often reports error. You need the latest iTunes on PC.

You need to click Help in iTunes and then select Check for Updates.

iTunes Check For Updates

#6 Keep iPhone screen unlocked

iTunes can’t import data to iPhone because of privacy issues. You need to unlock iPhone screen when you transfer data between iPhone and computer.

Go to iPhone Settings > select Display & Brightness > select Auto-Lock > check Never.

Display Brightness

#7 Disable Antivirus on computer

Sometimes security software would stop iTunes from working so you need to disable the programs like Malwarebytes or McAfee when you update iPhone.

#8 Manually update iPhone iTunes

If you click Update in iTunes but get error 4000, you could try manually update iPhone in iTunes.

1. Connect iPhone to computer with USB cable. Click the device icon and then select Summary section.

2. Make sure you have downloaded the latest iOS update in iTunes. You can find it in C: \Users\User Name\AppData\Roaming\Apple Computer\iTunes\iPhone Software Update. If you haven’t downloaded the right version of iOS in iTunes. Go to to download the firmware to computer.

3. Press and hold SHFIT Key and click Update in iTunes.

4. Select the iOS update from your computer and open it to install the latest iOS.

#9 Enter Recovery Mode to update iPhone

If iPhone still could not be updated for error 4000 after you try every method, there is the ultimate way. It is proved that updating iPhone could be successful after Recovery Mode.

You need to know that putting iPhone into Recovery Mode might make you lose all the data on iPhone, so it is very necessary to backup important data before you execute this method. Clicking Update is safe but don't click Restore.

1. Put iPhone into Recovery Mode.

There are different operations for different iPhone. Connect your iPhone to iTunes with USB cable and pick the right method for your iPhone to enter Recovery Mode.

◆ iPhone 8 or later: Press the volume+ button and then quickly release. Press the volume- button and then quickly release. Press the power button for seconds and then iPhone would enter recovery mode.
iPhone 7 and iPhone 7 Plus: Press both the power button and volume- button for seconds and the iPhone would enter recovery mode.
iPhone 6s or earlier: Press both the power button and the Home button for seconds and then iPhone would enter recovery mode.

2. You could see the pop-up below in iTunes and click Update.

iTunes Repair iPhone Recover Mode

How to easily backup iPhone before updating iPhone?

Now you know how to fix error code 4000 in iTunes but your important data should be saved because data disaster could happen at any moment.

AOMEI MBackupper is a brilliant professional iPhone backup software. You can use it to save photos, videos, music, contacts, and messages from iPhone to computer.

What's more, you could use this software to directly import photos from PC to iPhone. It is better than iTunes because photos synced from iTunes will be removed if you enable iCloud photos on iPhone.

  • Totally Free: Backup and restore unlimited iPhone with AOMEI MBackupper.

  • Select Data: Preview and select all the items you need from iPhone.

  • Incremental Backup: Backup iPhone in a professional way to save time and space.

  • Widely Compatible: Backup any iPhone with AOMEI MBackupper, including iPhone 12/SE 2020.

Download AOMEI MBackupper to computer and follow the steps to easily backup your iPhone:

Step 1. Connect iPhone to computer with USB cable and select Custom Backup.

Custom Backup iPhone

Step 2. Click the icon of every feature to preview and select iPhone data. Click OK to return.

Select iPhone Data

Step 3. Click Start Backup to quick save everything you select.

Click Start Backup

Bonus Tips: How to install previous iOS?

What if you don’t like the present iOS on iPhone? In fact, you could install any version of iOS by yourself. Before you downgrade iOS, remember to backup iPhone because downgrading iOS would factory reset iPhone.

1. Go to to download the right installation package of iOS to computer.

2. Connect iPhone to iTunes and click the device icon.

3. Press and hold the SHIFT Key and click Restore iPhone.

4. Select the folder you have downloaded to reinstall the iOS.

Downgrade iOS 14 to iOS 13 via iTunes


You could update iPhone experience new features and fix the bugs in the present iOS. If you have problem that you can’t update iPhone for error 4000. You could follow this guide to know why you can’t use iTunes to update your iPhone.

Besides helping you solve this issue, this guide also provides useful tips for you to backup iPhone and install previous iOS. To protect iPhone data, you need to use AOMEI MBackupper to backup iPhone regularly.

Don't forget to share this guide to help more people.