calls to graph calendaring api for create and update timing out frequently

Question

We have an application that creates and updates Outlook calendar invites on behalf of our users. Recently, we've started seeing numerous timeouts when calling the Microsoft Graph API.

These errors are sporadic, follow no discernible pattern, and provide minimal diagnostic information. They are not hard failures — retrying after some time typically succeeds, making them feel like the equivalent of a 500 error.

The issue primarily appears to be impacting our Australian customers. The only error message we receive is:

Microsoft network/client error: Error executing the request

We're unsure how to proceed, and this is causing a significant impact for our customers.

Answer 1

2026-02-16 00:48:52.405 [-----------no-request-id------------] ERROR - Microsoft network/client error: e1c27658-1a74-431d-ae64-17e66dc57469, eventId: AAMkAGZiMjA4MjM3LWQ3OWUtNDk0Ny05ZTU3LTJhODc0NzZmNDk3NABGAAAAAADJj3EOG3YgTIVii7NBoIGMBwALaTI9emjHSKEsgx3awAjBAAAAAAENAAALaTI9emjHSKEsgx3awAjBAADv0cfDAAA=
2026-02-16T02:40:39.902Z
2026-02-16 02:40:39.902 [-----------no-request-id------------] ERROR - Microsoft network/client error: e1c27658-1a74-431d-ae64-17e66dc57469, eventId: AAMkAGZiMjA4MjM3LWQ3OWUtNDk0Ny05ZTU3LTJhODc0NzZmNDk3NABGAAAAAADJj3EOG3YgTIVii7NBoIGMBwALaTI9emjHSKEsgx3awAjBAAAAAAENAAALaTI9emjHSKEsgx3awAjBAADv0cfDAAA=

example traces

Answer 2

It sounds like you're experiencing intermittent timeouts when calling the Microsoft Graph API for creating and updating Outlook calendar invites. Here are some steps you can take to troubleshoot and potentially resolve these issues:

1. Check for Known Issues: Before diving deeper, verify if there are any known issues with the Microsoft Graph API that might be affecting your calls. You can check the Microsoft Graph known issues website.
2. Review Throttling Limits: Ensure that your application is not exceeding the throttling limits set by the Microsoft Graph API. If you exceed these limits, the API may return a 429 (Too Many Requests) status code, which could lead to timeouts. You can find more information about throttling limits here.
3. Log Unique Request IDs: When making requests to the Microsoft Graph API, generate a unique client-request-id for each request. This can help you track and correlate requests and responses, especially when debugging issues. Make sure to log the request ID and date from the HTTP response headers as well.
4. Check for SNAT Port Exhaustion: If your application is hosted in Azure, consider checking for SNAT port exhaustion, which can cause connection issues. You can find diagnostic information related to this in the Azure portal under Diagnose and solve problems > SNAT Port Analysis for your API Management instance.
5. Monitor EWS Logs: If you have access to Exchange Web Services (EWS) logs, check them for any entries related to your requests. This can provide insights into the time taken for requests and help identify any patterns or issues.
6. Retry Logic: Since you mentioned that retrying after some time typically succeeds, ensure that your application implements robust retry logic with exponential backoff to handle these intermittent failures gracefully.

By following these steps, you may be able to identify the root cause of the timeouts and improve the reliability of your application when interacting with the Microsoft Graph API.

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References:

• How to debug Microsoft Graph API calls
• Microsoft Graph error responses and resource types