I got the software update pop up window saying I need to install new software on my Mac before it can connect with my iPhone, but it does not tell me what software will be installed. Will it be a whole OS upgrade or a patch? I am currently running Mojave 10.14.6.
MacBook Pro 13″, macOS 10.14
Nothing bad will happen. That is normal and will not install Catalina. See:
I had that recently when I upgraded an iPad to iPadOS 14 using iTunes on my iMac running Mojave.
The download is NOT a system software upgrade. I had Mojave when I allowed the patch and I still have Mojave. No problem.
The download is small and took maybe two minutes to install. I believe it patches iTunes to allow you to continue to do backups, upgrades, and synching of your device through iTunes as before.
I did this and it still is not recognizing my phone in/opening iTunes. I also tried this on an older MacBook Pro running an older iTunes.
I've done a reset on my iPhone 7. It is running iOS 14.0.1.
Ports are clean. Different official Apple cords used. Date/Time is synced.
iPhone 7 with IOS14.0 won't connect with Mac
