Note: English-language articles on this website are usually machine translated.
A few days ago, Outlook Classic in Microsoft 365 experienced an issue where right-clicking caused the application to crash. This has been fixed in the latest monthly builds. If you are still experiencing the problem, update Office.
On the Current Channel, the recent version is:
Version 2606 (Build 20131.20126 Click-to-Run)
This version — or a later version — fixes the issue.