I created an album that was linked to the default images. I used settings to link to hi-res images and when I then test the album, I get a "file missing" error when I click on any thimbnail image. I'm still in the file creation/testing screens. How can this happen???

Hi-res images no longer exist in jAlbum. They were removed in jAlbum 15, almost eight years ago. The entire "image linking" settings panel has been revised.

Please update to the latest release of jAlbum. Older versions are not supported.

If you're actually referring to having the thumbnails lead directly to the original, non-scaled images, there are two settings to check.

Under Images > General > Include, check only Originals.

But then, under Images > Advanced, make sure you've checked Copy originals if needed. Without that, the originals aren't copied into the completed album, which will produce "broken" links.

(That second option is there to address the rare situation in which the user is keeping the originals on his server, and doesn't need to have them copied locally.)