iTunes 12.8.2.3 won't connect with iPhone iOS 14.2 under Mac OS 10.11.6

For iOS 12 you need iTunes 12.8.0.150 or better running on OS X 10.11.4 or better. See How to upgrade to OS X El Capitan - Apple Support if required. iOS 13 & 14 require iTunes 12.8.2.3 or above.

Assuming a suitable version of iTunes is in place then in Finder use the menu item Go > Go to Folder..., copy the following text, paste it into the dialog box and press enter:

/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/Current/Resources

Unlock your device and connect it to USB. Double click on MobileDeviceUpdater in the folder that has opened. It should notify you of a software update. Install it and iTunes should hopefully recognize your device.

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Reboot your router and computer and try again? You've already reinstalled iTunes which would be my other suggestion. You might also want to check for malware with a trial of Malwarebytes in case you have something that is tying to spy on your connections to Apple's servers.

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Are you doing Unlock your device and connect it to USB first? You might also try the reset trust settings advice from About the 'Trust This Computer' alert on your iPhone, iPad, or iPod touch - Apple Support.

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I have the same issue. The first time ran the mobile device updater something happened. And after a fresh iTunes install of 12.8.2.3

allowed me to connect to iTunes and Photos. But somewhere after that nothing happens, the macbook won't see the phone. Console shows it trying to mount the phone, but nothing happens, and a message comes up in iTunes "The operation has timed out".

2015 MBP running 10.11.6

iTunes 12.8.2.

Photos 1.5

All OS X 10.11.6 updates installed

I have tried fresh install on phone,reset trust settings...

It seems like a software issue.

If I try the phone in a guest account it mounts and I even can see it in my user account. But after a while something happens that the phone no longer is recognized.

Another ideas?

Are you using a VPN? If so turn it off? Check for malware with a free trial of Malwarebytes. Reboot router and computer once more. Try reinstalling iTunes 12.8.2.3 while your device is connected to your Mac and unlocked. Reset the trust settings on the device and try again. Try the MobileDeviceUpdater again. Try with your Mac in Safe Mode. Reinstall your operating system as a last resort. Given it works in a new user account perhaps you'll have to migrate all your settings and documents to that one. Try Apple Support and see if they have any bright ideas.

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Another ideas?

Not really. You could try reinstalling iTunes 12.8.2.3 to see if it helps.

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