When using Chrome, PDF files will generally open without issue, however, sometimes you may open a PDF file and experience a "Failed or Forbidden" message or a few pages of the PDF followed by a greyed out screen.  If this happens you can switch your Chrome PDF setting to download the PDF instead of viewing it in the browser.  

In Chrome

1.  On your computer, open Chrome
2.  At the top right, click More 
3. Scroll down to "Settings"
4. Then "Privacy and Security"
5. Choose "Site Settings" under Privacy and Security
6. Scroll down under "Content" choose PDF documents (this may be under 'additional content settings')
7. Toggle this to the "On" position (indicated when highlighted in blue)