Occasional 412 errors when listing calendars using Microsoft Graph API

Monty123 1

I'm making GET requests to the following endpoint:

https://graph.microsoft.com/v1.0/me/calendars

Roughly 3.5% of these calls fail with a 412 error code. The same call will succeed a few minutes later. There does not seem to be any pattern to the failures.

Is this a recognized problem? Is there a solution other than ignoring the 412s and trying again later?

Deva-MSFT 2,256 Reputation points Microsoft Employee

2021-02-15T15:59:53.79+00:00
HTTP 412 means that precondition failed; in other words, a precondition provided in the request (such as an if-match header) does not match the resource's current state.

Hows your API call look like?

Do you use any precondition with it?

Outside of your code, can you repro the issue with POSTMAN/Microsoft Graph Explorer as well?

Share the detailed error response (with requestid, timestamp) that you received.
Monty123 1 Reputation point

2021-02-16T16:51:21.983+00:00

Full request:

GET https://graph.microsoft.com/v1.0/me/calendars

No payload or query string parameters, and no precondition.

Full response:

412 {'error': {'code': 'ErrorIrresolvableConflict', 'message': 'The send or update operation could not be performed because the change key passed in the request does not match the current change key for the item.'}}

Don't have time to reproduce due to its transient nature.