However, anyone running OS X Yosemite 10.10.5 specifically should avoid updating to iTunes 12.8.1 for now, as users across the MacRumors Forums, Twitter, Reddit, and Stack Exchange report that the update somehow breaks Safari 10.1.2, the latest version of the browser for OS X Yosemite.
After updating to iTunes 12.8.1, some users have encountered the following error message when opening Safari on OS X Yosemite:
Safari cannot be opened because of a problem.
Check with the developer to make sure Safari works with this version of Mac OS X. You may have to reinstall the application. Be sure to sure to install any available updates for the application and Mac OS X.
One user on Stack Exchange believes that the iTunes 12.8.1 update may update /System/Library/PrivateFrameworks/MobileDevice.framework to a version incompatible with Safari 10.1.2, but the cause is not entirely clear. We’ve flagged the issue with Apple and asked if and when a fix will be available.
In the meantime, workarounds include using an alternative browser such as Firefox or upgrading to a newer macOS version — of course, those still using OS X Yosemite likely don’t want to or can’t upgrade. Updating to iTunes 12.9 is not possible on OS X Yosemite, as that version is only compatible with macOS Mojave.
We’ll update this article when a fix is available.