iPhone software update fails with 'file was corrupt' error

If you are attempting to update the iPhone using a manually downloaded IPSW file and the update is failing, one possible reason is that the IPSW file is either corrupted, incomplete, or simply too old for the iOS version currently installed on the iPhone.

In this case, the version mismatch is particularly significant. The Mac Finder screenshot shows iOS 16.2, whereas the iPhone screenshot shows iOS 26.7.1. This indicates that the IPSW file being used is for a much older iOS release and is therefore unlikely to be suitable for updating an iPhone that is already running iOS 26.7.1.

Second, a jump from iOS 16.2 to iOS 26.7.1 is a very large iOS version jump, and available storage on the iPhone should be addressed before attempting the update. The iPhone needs sufficient free space not only for the iOS installation package but also for the temporary files required during preparation, verification, extraction, and installation. If the device is already low on storage, the update may fail even though the IPSW has been successfully downloaded to the Mac.

Therefore, before troubleshooting the update further, I would recommend checking:

1. The exact iOS version currently installed on the iPhone.
2. The exact iPhone model and whether the IPSW matches that model.
3. The IPSW file's integrity and download status—a corrupted or incomplete file can cause installation errors.
4. Whether the IPSW is still being signed by Apple.
5. The available storage on the iPhone, particularly when moving from iOS 16.2 to iOS 26.7.1.
6. The available storage on the Mac, since Finder may also require working space while processing the IPSW.

In short, if the intention is to move from iOS 16.2 to iOS 26.7.1, I would not immediately assume that the problem is with Finder or the iPhone itself. The very large iOS jump, the amount of free storage available, and the validity and compatibility of the IPSW should all be verified first.

Update options:

There are only 2 ways to update an iOS/iPadOS. Know how to...

• Update Over-the-Air (OTA) —> Update your iPhone or iPad - Apple Support (IN)
• Update using iTunes/Finder —> Update your iPhone, iPad, or iPod touch - Apple Support (IN)

You may get better and prompt responses if you may kindly provide the iPhone Model that you have and the iOS version if it is known to you and re-post.

With the limited information that you have provided, It is hard to even guess the problems faced by you. 

You may get faster and better responses to your query by --> Writing an effective Apple Support Commun… - Apple ...

Please re-post with detail so that someone else can help.