It's Update Manager that is incorrect. :-) An adjective phrase should be hyphenated only if it comes before a noun, not after. An up-to-date system is up to date.
I suggest that this be fixed by using the text shown in <https://wiki.ubuntu.com/SoftwareUpdates#check-interactive>: "The software on this computer is up to date.".
It's Update Manager that is incorrect. :-) An adjective phrase should be hyphenated only if it comes before a noun, not after. An up-to-date system is up to date.
I suggest that this be fixed by using the text shown in <https:/ /wiki.ubuntu. com/SoftwareUpd ates#check- interactive>: "The software on this computer is up to date.".