Recurrence exception sync fails after multiple modifications (participants → time) with "object has been deleted" error

[GadzhiKassiev]

Incorrect behavior of CalDavSynchronizer has been detected. The error occurs regardless of the mail service. Scenario for reproducing the limitation on the part of the Caldav library and Outlook:

1. Create a chain of meetings, for example, from 9:30 to 10:00 every day from Monday to Friday with several attendees.
2. In Outlook, synchronize with mail service.
3. In the mail service, change one of the events in the chain by deleting/adding attendees.
4. Synchronize in Outlook.
5. Check in Outlook that the event is synchronized: open it in the calendar. The first synchronization should be successful.
6. In the mail service, change the same event again by changing the meeting time.
7. Synchronize in Outlook.
8. Expected result: synchronization is performed;
   Actual result: synchronization is not performed, the CalDavSync reports log displays the error “The operation cannot be performed because the object has been deleted.” in the warnings.

If you do not open the event for viewing in step 5, further synchronization is performed without errors.
The problem is probably that Outlook locks the event instance for a certain period of time after it is opened for viewing/editing.

I am ready to provide additional information.