I just wanted to post this because we have been having this issue for months and it has been driving us nuts.
Our issue is described exactly in these two articles:
Where clicking on 'archive explorer' or 'search vaults' icons within Outlook would not open the HTML redirect vault entry point but would rather just open a blank screen. We opened a ticket with Symantec on this but banging our heads against the wall proved more fruitful as they contiunally kept requesting the same log files over and over again.
In our case we eventually pin pointed the problem to an Outlook add-in conflict with our DMS service, NetDocuments EMS. It turns out that Symantec rewrote how their add-in interacts with Outlook past version 10.0.2 and if we install anything past v.10.0.2 our clients receive the symptoms mentioned above. Removing the EMS plug-in resolves the issue.
We have submiited this to Symantec a few weeks ago and are supposedly looking into this conflict with their developers. If they ever get back to us I will post their response.
I hope this helps someone using the lasted EV Outlook add-in and is having a similiar conflict with the NetDocuments or any other add-in.