Hi there the Outlook version is :
1.2024.814.200 (Production).
Client Version is 20240809006.12.
WebView2 Version is 127.0.2651.105.
The issue seems to have been resolved. It seems that the user had scheduled too many events.
To answer your questions:
Can you verify if the issue happens on all you outgoing emails? It did not happen in outgoing emails but on scheduling assistant while trying to schedule an event.
Are you able to receive emails? Yes sending and receiving is not the issue.