Elsevier has acknowledged a problem with opening PDFs in ScienceDirect in some browsers using the Adobe plugin, on some versions of Windows. They are working on this problem.
In the meantime, try one of these workarounds:
1. Save the PDF locally before opening it.
2. Change preferences in Adobe Reader:
- Edit –> Preferences
- Select “Internet,” then uncheck “Display PDF in browser”
- Select “Okay,” then close Reader and reopen your browser.