Sunday 27 May 2018 not previewing PDF files

I was unable to view PDF files in the In the end I found it was because my browser settings were set to download files. To fix:

In Chrome
Open chrome://settings. Click on the Advanced link at the bottom. Turn the "Ask where to save each file before downloading" to OFF.

In Firefox
Go to Options. Under applications, type in PDF. Set the action to "Preview in Firefox".