Not all Mac keyboard shortcuts can be disabled. Before you map a Mac keyboard shortcut in Horizon Client, you must disable the shortcut in System Preferences on the Mac client system.Alternatively, the keyboard shortcut might trigger an action in both the operating system and Horizon Client. For example, the keyboard shortcut might trigger an action in the operating system and Horizon Client might not respond to the shortcut. If you map a keyboard shortcut, how the shortcut behaves on the Mac client system depends on how the operating system manages the shortcut.If you attempt to map one of these operating system keyboard shortcuts in Horizon Client, the behavior of the shortcut on the Mac client system and in the remote desktop or published application can be unpredictable. For example, Command-Tab and Command-Space bar are common keyboard shortcuts on Mac systems and Ctrl+Esc and Alt+Enter are common keyboard shortcuts on Windows systems.

Mac and Windows both include default keyboard shortcuts.

Windows mac keyboard shortcuts