c# - Cancelling Item_Open causes crash -

i writing office addin using c# , microsoft.interop libraries. when cancel opening of appointment in item_open event setting cancel property false, causes outlook crash appcrash. crash happens when opening appointment of recurring series attendees.

this new in 2016. in 2010 , 2013 used work.

has idea how working in 2016?

i tried identify problem in code example found here (which works 2016 in other regards) breaks if set cancel true in appointmentitem open event.

edit: found out happens if disable cache mode

when cancel opening of appointment via setting cancel bool false in item_open event causes outlook crash

to cancel default action need set cancel parameter true. setting cancel parameter false shouldn't prevent item opening in inspector window.

make sure no other add-ins enabled in outlook.