According to PhoneArena , some members of the Apple community said they were unable to download iOS 17.3. Some received a pop-up saying the update could not be verified, so iOS 17.3 would not be available. The pop-up gave users two options: Try Again or Remind Me Later. Some Redditors said that simply tapping Retry was enough to install iOS 17.3. However, one user said that his wife's iPhone 12 Pro Max could not do it.

After the issue was raised, a user named ShibamMandal suggested that iPhone users who are unable to install iOS 17.3 should go to Settings > General > iPhone Storage . From there, delete the iOS 17.3 update from the list of apps. Next, force the iPhone to restart by following these steps:

• Press and quickly release the volume up button.
• Press and quickly release the volume down button.
• Press and hold the power button.
• When the slider appears, slide to turn off iPhone.
• Then, hold down the power button to turn your iPhone back on.

After restarting your iPhone, go to the Settings app > General > Software Update to try reinstalling iOS 17.3. Other users say this is what they've used to help fix the problem of 'stubborn' software updates downloading.

One thing to note is that while downloading the update, users should try to prevent the internet connection from being interrupted as some believe that this is the main reason why the software update cannot be installed on their iPhone.