Content approval and recurring event

A few days ago I experienced an interesting issue when using the Calendar E-Mail Extension with content approval enabled.

This is what happened:

1. I created a new recurring event
2. I approved the event
3. I deleted a single occurrence of my series event

When I then logged in as another user (without manage lists and approval permissions), the deleted occurrence is still visible and if I clicked on it, I received the error “Item does not exist. It may have been deleted by another user.”

So let me explain what happens if a single occurrence of a repeating event is deleted or changed.

If an instance of a recurring event is changed or deleted, SharePoint adds a new event to the list with a different event type.

There are 4 types of events:

• 0 – Single Event
• 1 – Recurring Event
• 3 – Deleted instance of a recurring event
• 4 – Recurrence exception

So for example, if I delete a single occurrence, a new item with Event Type 3 will be created.

So the problem now is that if content approval is enabled on the calendar, this newly created item is pending. If a user without manage lists or approval rights opens such an occurrence, it displays the “item does not exist” message.

If it’s a recurrence exception, the user who made the changes can at least access the exception and approve it manually, but if it’s a deleted instance it’s not easy to access the item, especially in the calendar view.

A deleted instance is only visible in the “All events” view and can be identified by the title “Deleted: [Title]”.

One possible workaround would be to approve newly created items automatically with a simple SharePoint Designer Workflow if the EventType is 3 or 4. Make sure the workflow is configured to start automatically when an item is created.