Flow:

> Using an Outlook 365 GET request to retrieve all users of the Outlook workspace

> Looping over the array of objects by using the action, "Apply to Each"

> Dynamically passing in the ID property, "item()?['Id']", to:

"Get User" call
"Get User Calendar" call.

Image (simplified version):

> Hard coded by copying the Id
> Image below was used to test individual users that the problem was occurring for.

> Assume the Id is correct and the mailbox is active

Problem Details

> Get User always succeeds so we know User Id is correct

> Get User Calendar will fail for 10-20% of users (see below).

Out of 100 Outlook Users, 10-15 result in a 404:

"error": {

"code": "ErrorItemNotFound",

"message": "The specified object was not found in the store."

}

The number will occasionally change. Some users will result in a 200 then a 404 randomly, vice versa.

This problem will occur for new hires that would be lower in the organization tree and employees that are higher in the organization tree than the user calling the API.

What are some possible reasons for this?

Categories:

General topics

Problem

List events

https://learn.microsoft.com/en-us/graph/api/user-list-events?view=graph-rest-1.0&tabs=http

GET /users/{id | userPrincipalName}/events

GET /users/{id | userPrincipalName}/calendar/events

When looping over all the users in my workspace, the "List Events" api would sometimes result in a 404 ItemNotFound error. Even if nothing was changed (at least on my end), I would sometimes receive different results.

Workaround / Solution

List calendarView

https://learn.microsoft.com/en-us/graph/api/user-list-calendarview?view=graph-rest-1.0&tabs=http

GET /me/calendar/calendarView?startDateTime={start_datetime}&endDateTime={end_datetime}
GET /users/{id | userPrincipalName}/calendarView?startDateTime={start_datetime}&endDateTime={end_datetime}

Instead of calling List Events, I decided to call "List Calendar View". This returned the same object that I was looking for when calling "List Events" except more predictably and reliably.