Install Unpaywall if Academia.edu stops downloads. It will show you legal OA copies as you browse and let you open them with one click. Free, quick, and it works on a lot of papers.
If you paste in a DOI or title into Open Access Button, it will check thousands of repositories for the file. If none are found, it can email the authors to get a legal copy. This works in your browser itself.
Click the [PDF] or [HTML] links on the right side of Google Scholar or search for "All versions" to find free copies. The fastest way to find papers hosted by authors is to use this method.
The arXiv is for math, CS, and physics, PubMed Central is for medicine, and DOAJ is for fully open papers. These hold a lot of free full books.
If you still can't get it, you might want to file a report on Xolvie to get it fixed.
