Outlook 2013 calendar invitation.

Hello,

I solicits your help for a display issue invitations in outlook 2013 with zextras:

When I received the invitation message it is accompanied by an ics attachment and not with buttons "accept" "temporary" "decline"

When I double click on the ICS file this error appear:

"The operation failed. An object could not be found"

The event is added to the calendar, but we do not know what date given that we do not view it.

This problem does not occur when I use an account outlook.com

Do you have any idea about it?

Thank you in advance,