The issue is that older versions of Adobe Acrobat (Not Acrobat Reader) are not compatible with the newer IE security model. Adobe Acrobat controls IE’s ability to display a PDF inside its browser. All you can do is turn off the setting inside Adobe Acrobat that controls where the PDF opens. Please see the instructions below.

However, at this time however, this is a per user setting. Each person will have to change this setting on his/her own. The Office of Information Systems is looking to see if there is a way to control this with Group Policy. An update will be provided when available.

Please note that Firefox and Chrome are not affected by this issue.

Solution:

Disable opening PDF files in the browser. This solution involves changing the Adobe Acrobat settings so that the PDF files do not open in the browser window. Depending on your browser, the PDFs made automatically open in their own window or the download option may appear.
  • Open Adobe Acrobat.
  • Click on the ‘Edit’ menu then ‘Preferences’.
  • Click on ‘Internet’ on the side bar.
  • Under ‘Web Browser Options’ untick ‘Display PDF in browser’.
         
  • Click ‘OK’ to save the changes.