Assume that you receive a calendar sharing invitation that's created from Microsoft Exchange Server 2013. When you open the invitation in Outlook 2013, Outlook 2013 crashes. This issue occurs when the Read all standard mail in plain text option in File > Options > Trust Center > Trust Center Settings > Email Security is selected.
To fix this issue, install April 2, 2019, update for Outlook 2013 (KB4464507).
You can disable this fix, depending on your requirement. To do this, change the value of the PstSharingFixEnabled registry key to 0 in the following location:
The default value of this registry key is 1.