7 Solutions to Fix Unable to Install Update An Error Occurred Installing iOS 16/15 & iPadOS 16/15

Solution 1: Check Compatibility to Fix Unable to Install iOS 16/15

The first and the most basic solution that can help you fix iOS 16/15 unable to install update error on your iPhone or iPad is to check the compatibility of your device and see if it supports iOS 16/15 update. In case your device is not compatible with iOS 16/15. Here's a list of iOS 16/15 Supported devices and iPadOS 15 supported devices.

Solution 2: Force Restart Your Device

Force restarting your iOS device is another way to fix the iPhone won't install update issue on your iPhone or iPad. A force restart can help you delete all the junk files from your device, and it will moreover refresh your device's memory. Force Restart is generally considered as a quick fix to fix all the minor system glitches related to your iOS device.

Here's a guide on how to Force Restart your iOS device:

Force Restart iPhone 8 and Later

1. Step 1: Fastly press and release the "Volume Up" button.
2. Step 2: Now, quickly press and release the "Volume Down" button.
3. Step 3: Lastly, long-press the "Side" button until the Apple Logo appears on the screen.

Force Restart iPhone 7/7 Plus

Press the Power button and volume down button simultaneously and hold them. Let go of the buttons when you see the Apple logo on the screen.

Force Restart iPad with Home ID

1. Step 1: Press and hold the "Top" button unless the "Power OFF" slider appears on the screen.
2. Step 2: Now, drag the slider and wait for 30 seconds for your iPad to turn OFF.
3. Step 3: Lastly, press and hold the "Top" button until the Apple logo is visible on the screen.

Force Restart iPad with Face ID

1. Step 1: Long press either the "Top" button or the "Volume” button until the "Power OFF" slider appears.
2. Step 2: Simply drag the slider and wait for 30 seconds for your device to turn OFF.
3. Step 3: Finally, press and hold the "Top" button until the Apple logo appears on the screen.

It is this easy to force restart your iPhone or iPad. If this solution didn't work to fix your issue, then try solving it with the next solution.

Solution 3: Check Storage to Install iOS 16/15 Update

The iOS 16/15 update is around 3GB. If you are not able to update your iPhone to iOS 16/15, then there are chances that your iDevice is running low on storage. So, always check if your iPhone has sufficient storage to install the iOS 16/15 update.

Go to Settings > General > [Device] Storage. You may see a list of recommendations for optimizing storage space on your device, followed by a list of installed applications and the amount of storage space used by each application. Tap the name of an application to learn more about its storage.

Here are some tips to free up available storage to install iOS 16/15:

1. 1. Offload unused apps.
2. 2. Auto delete old conversations.
3. 2. Delete unused apps.
4. 3. Depending on the application, you may be able to delete some of the documents and data.
5. 4. Transfer large media files to computer and then delete them from your iPhone.

Solution 4: Delete Update and Re-download the New iOS 16/15

If none of the above-stated methods work to fix ios 15 unable to install update issue on your iPhone, then try fixing it this way. Some of the iOS users suggested that they are able to solve this issue by deleting and downloading the new iOS 16/15 update again. So, here's how to do it:

1. Step 1: Go to the "Settings" of your iOS device and tap on "General".
2. Step 2: Under "General," click on "iPhone Storage" on your phone.

3. Step 3: Here, find the iOS 16/15 update in the list, click on it and tap the "Delete Update" button.

   

4. Step 4: Next, go to the "Settings"> "General" again and click on "Software Update." You can then download the latest iOS 16/15 update on your iOS device.

   

After uninstalling the old iOS installer and re-installing it, you will be able to get the new iOS update without much hassle successfully.

Solution 5: Check Network When You Are Unable to Install iPhone Update

Often, there are chances that network settings cause them unable to install ios 15 error on your iPhone or iPad. So, to fix this issue, you must check your network settings and make sure that the "Cellular" network is turned ON. If you don't know how it works, then here's a step by step guide below:

Go to the "Settings" on your device and tap on "General" > Reset > Reset Network Settings.

You can now check if the problem is resolved! In case the problem still persists, then try fixing it with the upcoming solution.

Solution 6: Update to iOS 16/15 on Computer

If an error occurred installing iOS 16/15 and you are unable to install it, then updating your iPad or iPhone to the new iOS 16/15 via iTunes can prove to be a quick option. Here's how you can update your iOS device to the new iOS 16/15 with iTunes.

Step 1: Run iTunes on PC and connect your device to your PC via a USB cable. If you are using a Mac with macOS Catalina or later, select your device in the left sidebar of the Finder window.

Step 2: Now, tap on Summary> Check for Update in iTunes, and click General > Check for Update on Finder.

Step 3: Finally, click on the "Download and Update" option to update your device to the new iOS 16/15. This method is easy and quick to solve iPhone won't install update problems on your iOS device.

Solution 7: Fix iOS 16/15 Unable to Install Update without Data Loss

If you have to get your hands on all the above solutions, but they didn't work for you to fix your iOS update issue, then you can fix the error yourself in just a few minutes by using a third-party iOS System Repair software. UltFone iOS System Repair works flawlessly to fix over 150 iOS related issue in just a couple of minutes. The best thing that users love about this software is that it is easy to use, budget-friendly, and the iOS is automatically up to date along with the issue is solved.

• Enter and exit recovery mode on iOS 16/15/14/13 devices for free and in a click.
• Fix iOS 16/15 update, downgrade and jailbreak issues without data loss.
• Reset iPhone without passcode.
• Support all iOS versions and iPhone models, including the latest iPhone 14 series and iOS 16.

Below mentioned are the steps on how to use UltFone iOS System Repair to fix iOS 16/15 unable to install update error.

• Step 1 Download and run the UltFone iOS System Repair on a PC or Mac, and connect the device to the computer. Click Start button from the main interface.

  

• Step 2 On the upcoming interface, choose the "Standard Repair" option to proceed further. This repair mode won’t lead to data loss on your device. In case your iOS device is not detected, just follow the onscreen instructions to put your iDevice in DFU or Recovery to get it detected.

  

• Step 3 Now, on the next screen, hit the "Download" button to download the matched firmware package for your device. The iOS firmware is always up to date.

  

• Step 4 Once the matched firmware package is downloaded, tap on the "Start Standard Repair" button to fix the iOS issues on your device.

  

• Step 5 When the iOS system recovery is done, your iOS device will reboot automatically, and everything will be back to normal. The error has removed and the iOS is up to date on your device.

  

The Bottom Line

After reading this post, I hope that you’ve solved the problem “Unable to install update an error occurred installing iOS 15”. If you are using an iPad and having the error when installing iPadOS15, the solutions mentioned above are also helpful. Download UltFone iOS System Repair free and update your iDevice to the new iOS 16/15 without worrying about data loss.