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             A Fix for MobileDeviceUpdater's "Installation Failed"

   Adam Engst

   Of all the confusing processes Apple manages under the hood of macOS,
   few are as mysterious as MobileDeviceUpdater. When macOS requires a
   driver update to talk to a USB-connected iPhone or iPad, this software
   agent launches an installer that doesn't look like any other macOS
   activity.

   Despite MobileDeviceUpdater's alert sometimes causing people to wonder
   if it's malware or a phishing attempt, it's a real and necessary update
   that you must install to [1]enable your Mac to talk to your iPhone or
   iPad. Because you might update your devices on different schedules,
   it's common to end up in a situation where an older version of macOS
   doesn't know how to interact with a newer version of iOS or iPadOS.

   When you see this alert after plugging your iPhone or iPad into your
   Mac, go ahead and click the Install button. You'll see a progress
   window for downloading and installing. When it finishes, all will be
   well'or should be!

   The installation can fail. What do you do in that event? Apple provides
   no suggestions about how to resolve the problem if you see this dialog
   at the end of the installation.

   I hadn't experienced this problem until about a month ago when I
   plugged my iPad Pro into a 2020 27-inch iMac running macOS 12 Monterey.
   I wasn't even trying to sync; I just wanted to charge the iPad Pro, and
   I knew the iPad Pro would charge regardless. Although I never sync my
   iPad or iPhone over USB, I figured I'd agree to the installation to
   prevent future dialogs from nagging me. So you can imagine my
   irritation when an installer that I didn't even want to run failed. I
   tried restarting the iPad and the Mac, but neither made any difference.

   By happenstance, TidBITS reader [2]James Weil posted a solution on
   TidBITS Talk a few days later. It was my lucky day, and now it may also
   be yours. Follow these steps:
    1. In versions of macOS before macOS 13 Ventura, open System
       Preferences > Sharing; for Ventura, open System Settings > General
       > Sharing.
    2. Uncheck every service that's enabled.
       macOS 12 Monterey's version of System Preferences is shown above,
       but the same actions happen with switches in Ventura.
    3. Unplug the iPhone or iPad and then plug it back in.
    4. When MobileDeviceUpdater prompts you again, click Install. This
       time the software update should download and install correctly.
       Interestingly, the download took significantly longer to complete
       than when it failed, with a several-minute progress bar. That
       suggests the problem relates to the download.
    5. Enable the services in Sharing that you previously turned off.
       
   Because I successfully ran through this process in December, after
   James first posted, I was a little surprised when the same error
   cropped up again just now. It seems that the error can recur, forcing
   you to repeat this process each time new software updates cause your
   Mac and iPhone or iPad to fall out of sync.

   Confusingly, it didn't appear that any one of the enabled services was
   at fault. I turned off the three services I had enabled one at a time,
   attempting an installation before re-enabling the service and moving on
   to the next. I didn't expect AirPlay Receiver to be the culprit, but I
   could imagine a connection between MobileDeviceUpdater and either Media
   Sharing or Content Caching. But no: leaving any of the services running
   caused MobileDeviceUpdater to fail. As soon as I disabled them all, it
   downloaded and installed fine, just as James said it would.

   This solution is deeply unsatisfying, along the lines of voodoo fixes
   like rebuilding the Desktop or zapping PRAM in the old days. I'm open
   to suggestions for what might cause the problem, but without such an
   explanation, I can't guarantee that this solution will work for you. At
   least it's easy to try. (And if it doesn't work, post in the comments
   below, particularly if you find another solution.)

   Apple should put in the time to fix this problem once and for all.

References

   Visible links
   1. https://support.apple.com/en-us/HT208831
   2. https://talk.tidbits.com/t/fix-a-software-update-is-required-to-connect-to-iphone-fails-to-install/20793?u=ace

   Hidden links:
   3. https://tidbits.com/wp/../uploads/2023/01/MobileDeviceUpdater.png
   4. https://tidbits.com/wp/../uploads/2023/01/MobileDeviceUpdater-downloading.png
   5. https://tidbits.com/wp/../uploads/2023/01/MobileDeviceUpdater-failed.png
   6. https://tidbits.com/wp/../uploads/2023/01/System-Preferences-checked.png
   7. https://tidbits.com/wp/../uploads/2023/01/MobileDeviceUpdater-downloading-slowly.png
   8. https://tidbits.com/wp/../uploads/2023/01/System-Preferences-unchecked.png

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