If you're among the few still using Aperture to manage your photos on your Mac, it's time to move on. Apple has published a support page announcing that it's killing off the app, and macOS Mojave is the last version that it will work with. When macOS 10.15 ships this fall, you won't be able to run Aperture.
The solution that Apple provides is to migrate your libraries into Photos or Adobe Lightroom Classic. Obviously, Photos is Apple's built-in solution, and while Aperture hasn't been actively developed since June 2014, it was removed from the Mac App Store in early 2015 after Photos was introduced as the successor to that and iPhoto.
There are some caveats to migrating to Adobe Lightroom Classic though. While version 5.7 and later include a tool for migrating your Aperture library, the non-destructive adjustment layers for RAW files will not be migrated. You'll only be able to migrate JPEG files of edited images, although the original RAW files can also be moved.
macOS 10.15 will be announced in just over a month at WWDC, although it won't be publicly released until the fall. Naturally, Aperture should continue to work until you decide to update your Mac.