When I tried installing some of my files and they didn’t show up.
Perhaps the most important question is, how did you run the installers? Do you usually run them with default settings? Or do you click the “customise” button and manually point to your content location?
The problem is that the default settings aren’t always the actual default — the base content location has changed at least three times since the first version of DAZ|Studio was released, and the installers only know about the default settings at the time the installer was created. This will not change unless the installer is updated and recreated to fix a bug or to include Smart Content metadata.
I never run a default install, I always run them customised and check every time to make sure the installer is about to put things where it should. You’d be surprised to see how many times it guesses wrong, especially if you use more than one content folder (like I do), or you have a mix of content installers of all different ages (like I do).