Internet Explore Closed In A Flash When Opening attachment (PDF)
Cracking head trying to resolve this issue of Internet Explorer closed in a flash when trying to launch or open an attachment (PDF document to be precise), instead of prompting to save or launch the attachment.
To resolve the issue:
Internet Explorer - Tools - Internet Options - Security - Custom Level. Scroll all the way down to section 'Downloads' - 'File Download', select 'Enable'