FCP - download “Additional Content”

As Tom said, Smart Collections has nothing to do with Additional Content, apples to oranges.

When I do that, it opens System Settings > Software Update.

Attaching image of the Title Browser, which will not have the included templates if you haven't already downloaded the "additional content". Check for the title template category "Build In/Out" which is a collection included in the downloaded additional content. If you have it, you've done it. If it's missing, you need to download the templates for sure.

1, Verify what user name you're logged into on your Mac, and it matches what you've used in the App Store.

2, Hold down Opt and Cmd while launching FCPX and delete preferences.

Reboot the computer and try to download it again. Are you sure it's not already on the computer if you bought the application a few years ago? Perhaps you migrated the content from an earlier computer.

Did you purchase FCP or do you have the Trial version? I don't think Additional Content is available with the Trial.

How did you purchase 10.5.4? Did you ghost buy the current version on another computer?

These two, free tutorials are the recommended ones around here and can help you get up to speed quickly.

Steve at Ripple Training’s 60 minute FCP tutorial overview https://www.youtube.com/watch?v=HqUP7Zgeuck

Izzy Video tutorials. Older so the UI looks different but the concepts are still correct. https://youtu.be/_jvyrnQpR1E?list=PLp5SAgbM8S87n1qvv34-PAU2zMHLlXyfb

Additional Content isn’t in Smart Collections. Those are collections of your library content. See what you have in the Sound browser. Post a screenshot.

macProVideo.com has fantastic FCP tutorials, some of the best, also.