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Top 4 Ways to Fix iTunes Error 21 and All iTunes Problems

Most of iDevice users complained that iTunes 21 happens from time to time when they are trying to restore or update the iPhone, iPad or iPod touch using iTunes. If you've encountered error 21 in iTunes and are looking for a way to fix it. In this article, we will show 4 methods that are most likely going to work and fix iTunes error 21 when restore or update your iPhone/iPad in iOS 11/10/9/8.

 itunes error 21 fix

Common Causes of iTunes Error 21

  • Corrupt download or incomplete installation of iTunes software.
  • Corruption in Windows registry from a recent iTunes-related software change (install or uninstall).
  • Virus or malware infection that has corrupted Windows system files or iTunes-related program files.
  • Another program maliciously or mistakenly deleted iTunes-related files.

Runtime Errors such as "Error 21" can be caused by a variety of factors, so it is important that you troubleshoot each of the possible causes to prevent it from recurring.

How to Fix iTunes Error 21 When Restoring or Updating iPhone, iPad and iPod

There are several things you can try on how to fix itunes error 21. Below will show you 4 out of the most effective ways. Now let's take a look.

Method 1: Use Free Tenorshare TunesCare--Only 3 Steps

Most of time the problem occurred due to the problem with iTunes. Hence, we suggest you to get your iTunes error fixed first with the help of Tenorshare TunesCare, which is an all-in-one iTunes repair tool to fix all iTunes syncing problems and iTunes errors for free.

Free Download For Win 10/8.1/8/7/XP
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Free Download For macOS 10.13 and below
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  • Step 1: First of all, download Tenorshare TunesCare and click "Fix All iTunes Issues" to fix your iTunes on computer.
  • connect device
  • Step 2: If your iPhone performs abnormally, then just click "Repair iTunes" to start downloading iTunes drives for repairing.
  • abnormally
  • Step 3: After downloading the repairing drives for iTunes, Tenorshare TunesCare will automatically start to repair your iTunes.
  • repair
  • Step 4: After repairing, Tenorshare TunesCare will prompt you that iTunes is repaired successfully and your iTunes will automatically restart.
Free Download For Win 10/8.1/8/7/XP
Secure Download
Free Download For macOS 10.13 and below
Secure Download

Method 2: Disable/Remove Security Software

In some cases, your security software such as antivirus may cause the issue with your computer's connection with iTunes. To fix the issue, you'd better disable any security and antivirus softwares temporarily or remove them. As for those cannot be uninstalled completely security programs, you will need a cleanup software to help you remove them thoroughly. It's also a good idea to temporarily disable Firewall to see if it fixes the issue.

Method 3: Check Hosts File

Your host file might be preventing iTunes from contacting Apple's update server. In such a case, make sure that it is not blocking the communication. This can be done by removing the '' line in the hosts file. Go to Microsoft support site to see how you can check the host file on Windows or if you're on Mac, follow the steps below:

  • Step 1: Launch Applications and go to Utilities folder
  • Step 2: Open Terminal
  • Step 3: Type in the command: sudo nano /private/etc/hosts
  • Step 4: If it asks for a password, type in the password you use to sign into your Mac and then press the Return key
  • Step 5: Terminal will now display the hosts file as shown below. Scroll through the file and see if you can find an entry containing "". If you don't find this then the host file isn't creating any issues. Otherwise if you find this entry, then remove the entire line that contains "".
  • hosts file mac

Method 4: Fix iTunes 21 Error with Tenorshare ReiBoot--Ultimate Tool

To fix iTunes error without any data loss, a useful program you can have a try - Tenorshare ReiBoot. It comes to your hand. This powerful tool not only can put your device into Recovery mode within one click , but also help you fix all iPhone stuck problems, now get Tenorshare ReiBoot downloaded and installed on your PC, then let's get started.

Step 1: When iTunes pops up error 21 during iPhone update, and iPhone gets stuck on recovery mode (iTune logo and usb cable on iPhone screen), or white screen with black apple logo, please rurn Tenorshare ReiBoot, and click Exit Recovery Mode to get your iPhone out of recovery mode loop.

After this, your iDevice will get back to normal

fix ios stuck

Step 2. And then, you can click Fix All iOS Stuck, and download the latest firmware package to update your iPhone/iPad using Tenorshare ReiBoot.


Step 3: After system recovery, your iOS device will be updated to latest iOS version. You can enjoy it without any stuck or error.


Within the simple 3 steps, your iOS device can be fixed to normal.

With these four major methods, you can correct iTunes error code 21 on your own. We can easily know that the method 1 is the best to solve iTunes Error 21 for it's both feature of free and easy. Tenorsahre TunesCare never lets you down. Still, we recommend you to regularly manage and backup your files, you can also have a try of Tenorshare iCareFone, which is the best iTunes alternative to manage, backup and restore iPhone data.

/ Posted by Jenefey Aaron to iTunes Tips Follow @Jenefey Aaron