If Pubget can't find a way to get you the whole article, it will display the title and abstract, authors, and other relevant information together with a set of links to help you see if you can get access some other way. (Unfortunately, though, we usually find that if you can't get a paper through Pubget, you just plain can't get it.) This happens when the article is too old or too new (so there's no PDF yet), your institution lacks access, or there's a broken link somewhere.
If you think you should be able to get to a PDF but Pubget isn't doing it, please do let us know. It will help us make Pubget a better service for everyone. We really appreciate it.