For me, anyway, the problem was with Outlook's Add-Ins. The solution is to inactivate them. (You probably don't need them anway).
Go to file, Options, Add-ins (near the bottom), Manage COM add-ins (at the bottom), Go..." and uncheck all the boxes. Curiouslyly the ACT add-in had been unchecked (I had established a new profile), and checking it did no harm..