Apple transitioned away from iTunes on modern macOS systems, splitting its functionality into separate apps like Apple Music, Apple TV, and Podcasts. However, many users still seek out specific legacy versions like to manage older iPods, maintain compatibility with vintage Macs, or enjoy the classic, lightweight user interface.
Download iTunes 10.6.3 for Mac Free: A Guide to Legacy iTunes download itunes 101399 for mac free
If you are on macOS Catalina or later, you can use the Retroactive app to run iTunes versions 10 through 12. Important Compatibility Notes iTunes - Apple Apple transitioned away from iTunes on modern macOS
Fortunately, Apple still makes many old installers available on their official, secure servers, even if they aren't linked from their main website. The direct link for the macOS version of iTunes 12.6.5.3 (which is the build 101399) is: and Podcasts. However
This error happens if you try to open an older version of iTunes using a library file that was previously updated by a newer version of iTunes.