On some occasions, macOS may prompt to install the same update again, even though the update has already been installed. We can verify the update installed successfully, by checking in Terminal.
We can use Terminal to provide a list of the software updates that have been already installed on macOS
- Go to Finder -> Applications -> Utilties - Terminal
- Type the following command to show the list of software updates already installed on macOS "softwareupdate --history"
- Compare the name of the update and the date it was installed. If it matches the update that macOS is prompting to install again, reboot the macOS and the update notification should go away.
- You can also type "softwareupdate -l" to force your Mac to check Apple servers for anyupdate available on your system.