Error message while installing 17.4 iOS on my iPhone

Disable VPN

VPN or proxy connections might prevent your device from contacting the update servers.

Contact the VPN Service provider and disable it for the time being. In some cases, if the VPN server or network is configured to block certain domains or IP addresses, it might inadvertently block Apple's update servers. This could prevent your device from connecting to Apple's servers to download the update. Make sure that the VPN settings do not block Apple-related services.

Download Again:

• Get help with over-the-air iOS updates - Apple Support
• Remove and download the iOS update again

If you still can't install the latest version of iOS, try downloading the update again:

1. Go to Settings > General > [Device name] Storage.
2. Find the iOS update in the list of apps.
3. Tap the iOS update, then tap Delete Update.
4. Go to Settings > General > Software Update and download the latest iOS update.

If you don’t see the update in the list of apps or if the issue happens again, you need to update your device with iTunes.

Try updating iOS after each step.

• Try to Forget the WiFi network and add it again
• Try another WiFi network 
• Toggle Set Automatic Update off and then on
• Reset your network settings
• Force restart your device
• Remove any beta profiles, if applicable

Corporate Device check

If this is your corporate iPhone, it is important to reach out to the system administrator of your corporate. They will be able to assist you with any issues or concerns related to your device.

However, if it is your device, there are a few things to consider. Firstly, check if you have any profiles installed by your corporate, organization, enterprise, or school management. These profiles are typically used to manage certain settings or restrictions on your device.

If you do have a profile installed, and you no longer wish to keep it, you can follow the steps provided by Apple to remove configuration profiles on your iPhone. By doing so, you will eliminate the profile and its associated settings from your device. Install or remove configuration profiles on iPhone - Apple ...

In case you need further guidance or encounter any difficulties during the process, it is recommended to contact the system administrator of the organization that provided the profile to you. They will be able to assist you in removing the profile or addressing any concerns you may have.

Try updating using iTunes/Finder

• If everything fails: - Use iTunes or Finder (for macOS Catalina+) to update your device instead of over-the-air
• Get help with iOS updates and restore errors - Apple Support
• If you see an error when you update or restore your iPhone, iPad