By Michael | Last Updated
Q: I’m trying to install iOS 18 on my iPhone 15 Pro Max. But it keeps showing the message – An error occurred installing iOS 18. The package was downloaded. Why can’t I update my iPhone to iOS 18? What to do?
Most people choose to update their iPhone system to the latest version in order to pursue a better experience of using their device. But when you are updating iOS, your iPhone will show "Unable to check for updates”; "Unable to install updates”; "An error occurred while installing iOS 16, try again later or remind me" and so on. What causes the iOS update error and how to deal with it? In this guide, we'll walk you through common reasons why your iPhone may not update, and provide step-by-step solutions to fix the issue.
“Why won’t my iPhone update to iOS 18”, you may want to figure out why this happens before getting to the solutions for how to fix iPhone not updating to iOS 17/18. There are various reasons why the iPhone can’t update system situation occurs.
In this guide, we will cover 7 effective ways to fix iPhone won’t update issues and get your iPhone update to iOS 17/18.
If your device is not compatible with a particular version of iOS, attempting to install it will result in an unable to install update error with a detailed message “An error occurred installing iOS 18/17”. Therefore, it is essential to verify that your device supports the iOS version you’re trying to install.
iOS 18 Supported Devices:
If your iPhone has insufficient storage, it won’t be able to download or install the update. It is recommended to have at least 5GB of free space for iOS updates. So, when your device does not have enough storage space, the iOS update will fail.
You can check the available space on your iPhone by following the path: Open Settings > General> iPhone Storage. You will see a breakdown of how much storage is being used and which apps are taking up space. If there is not enough space for iPhone update, you should backup iPhone to PC and then delete apps, media, or files you no longer need to create room for the update.
The iOS update requires a Wi-Fi or other faster and stable network connection. A slow or unstable Wi-Fi connection can cause the update to freeze or fail. It is recommended to connect your iPhone to a reliable Wi-Fi network with a strong signal. Besides, you should avoid using cellular data for the iOS updates.
When the iPhone battery is low, the device will automatically pause iOS update, which will cause the iPhone update to fail. Thus, it is necessary to make sure your iPhone is fully charged.
If you see the error message “Unable to Check for Update” Or “Unable to Verify Update”, you can change another network to have a try. Or you can check the server’s status here.
When the server is overloaded, many users will be affected. You just need to wait for a moment and update your iPhone’s iOS version when the Apple server gets back to normal.
If the iOS update fails, you can restart the iPhone and try again. To restart the iPhone, keep pressing the side button and volume button to power off the iPhone. Then turn on your iPhone and attempt to update your iPhone again.
If the wireless update isn’t working, you can use iTunes (Windows) or Finder (macOS Catalina and later) to update your iPhone. This method often works better when the over-the-air update fails, especially if you’re running into connectivity or storage issues.
Step 1: Run iTunes/Finder and get your iPhone connected to the computer.
Step 2: Locate your iPhone and select it. In Windows computer, hit the Summary option on the left panel, then click Check for Update on the top menu of right panel. For Mac users, hit the General tab and then choose Check for Update option.
Step 3: Hit the option Download and Update. After that, follow the on-screen guides to update the iPhone.
There is a much easier way for you to update the iOS version. You can use iSunshare iOS Repair Genius to resolve the iOS update issues and update your iPhone to the newest iOS without causing data loss.
Step 1: Download and install the software on your Windows or Mac computer.
Step 2: Open the software and choose iOS Upgrade/Downgrade > Upgrade iOS option.
Step 3: Get the iPhone connected to your computer. After that, hit the Next button on the software.
Step 4: In seconds, your iPhone model is detected. And the compatible firmware is shown here. You can choose the firmware version and hit the Download button.
Step 5: OK, everything is ready. You can click the Start button to update the iPhone. Minutes later, you will get the successful message.
1. Why can’t I update my iPhone to iOS 18?
Several factors can prevent your iPhone from updating, including insufficient storage, a slow internet connection, outdated software, or bugs in the current version of iOS. Check your available storage and ensure your device is connected to a stable Wi-Fi network before attempting the update. More importantly, your iPhone model should be compatible with iOS 18.
2. How long does it take to download the new update on my iPhone?
It depends on the iOS version and your internet speed. Generally, it will take about half an hour to finish the downloading.
3. Can I update my iPhone 15 without Wi-Fi?
Yes, you can. But you cannot update the iPhone with cellular data. Instead, you can take advantage of iTunes/ Finder or third-party tool to perform a smooth update process.
Updating your iPhone to the latest iOS version, such as iOS 17 or 18, is crucial to enjoy new features, security patches, and performance improvements. However, if you encounter issues during the update process, don’t panic. By following the steps outlined in this guide, you can resolve common problems like insufficient storage, network errors, and software glitches.
Now, with these solutions at your fingertips, you can successfully fix any iPhone update issues and enjoy the latest iOS features in no time!
