Yes.  If you uninstall 2018, you'll have to reinstall (not repair) 2021.

Thanks.  Which is the more common approach?  To uninstall an old version prior to upgrading to a new version?  or to leave both versions installed?  or to migrate to a new computer and decom the old one once the new one is up and running.

SOP is to install the new, and ignore the old  Diskspace is cheap, and having old programs doesn't slow things down.

Thanks for feedback.  My concern is not so much about disk space utilization but more about configuration management (having consistent builds that are easy to replicate), as well as reducing attack surfaces (less software = less opportunities). Older software that remains can be exploited, especially when beyond end of support.  That said, I rarely see Sage products showing up in vulnerability reports.  

Thanks for feedback.  My concern is not so much about disk space utilization but more about configuration management (having consistent builds that are easy to replicate), as well as reducing attack surfaces (less software = less opportunities). Older software that remains can be exploited, especially when beyond end of support.  That said, I rarely see Sage products showing up in vulnerability reports.