encountered when users attempt to install older iTunes versions on newer macOS systems. If you are looking for the final stable version of this OS, it is macOS High Sierra 10.13.6 The Mystery of macOS 10.13.99
The error message requiring is a frequent point of confusion for modern Mac users. It typically appears when trying to install a standalone iTunes installer on a system running macOS Catalina (10.15) or later. The Core Issue: Why iTunes "Disappeared" itunes macos 10.13.99 download
The Digital Architect: The Legacy of iTunes on macOS High Sierra encountered when users attempt to install older iTunes