We had a user that suddenly couldn’t open any local or networked PDF files. I uninstalled, ran CCleaner, Adobe’s after acrobat cleaner, restarted the machine, and finally re-installed Acrobat. Same error came up.
This issue was solved by uninstalling EMET 5.1. Not really what I wanted to do but the user had to get work done.
Going to follow up with Adobe for a better solution.
The following link pointed me in the EMET direction.
https://forums.adobe.com/message/6830531
Hope this helps someone else out there….