Hmm it sounds weird that McAfee is involved.. but you can disabled the McAfee Add-ins in Outlook and if still the same issue to make sure is not McAfee go to the product guide under troubleshouting section and disabled all the McAfee components antil the last one that it will be completely remove VSE.
This issue is happening on outlook 2013 too.
But after HF installed it is solved already.
BTW I am wondering to know how to hide this Plugin too, because clients can disable the plugin easily which is against the securities.
Looking forward to find some clue on it.