From the release notes for jAlbum 34.3:
Fixed issue where UI controls that were disabled by skin could accidentally be re-enabled by jAlbum
This has produced a weird side effect. If you load a skin that disables a field, that field remains disabled no matter what else you do. Switching to a different skin won't re-enable that field. If your
default skin disables a field, you can
never access that field again, in any skin, unless you delete or replace
defaults.jap.
A quick illustration: launch jAlbum, and choose the
NoPages skin. This skin disables both
HiDPI thumbnails and
HiDPI images, since within the context of that skin, they make no sense. Now try to use any other skin - those two fields will always remain disabled.
Now choose
Neptune, which disables
Superimpose play icon onto video thumbnails, since the skin handles that itself. From that moment on, all
three of these fields are now disabled, in all skins.