Engage crashes when opened from the PowerPoint Ribbon

A problem has recently occurred on the 2 machines I run Studio 13 on.  All works fine until I open Engage from the PowerPoint Ribbon, the Engage dialogue box pops up but as soon as I click on anything within the dialogue box it crashes with a run time 462 error 

Studio has been deactivated and re-installed, PowerPoint has been repaired.  This is happening on 2 machines.  There are no issues with Quizmaker and Engage works if I click on edit button on the slide, it only crashes when I load it from the ribbon.  Our IT people have been really good and tried everything they can think of to fix it but nothing works.  I'd be grateful for any help on this.