Issues with Microsoft SSO (404 Error) – Solution

Category: FAQ

Version: 1.0

Last updated: Januari 22, 2026

Author: Any2Info

Summary

Over the past few days, some customers have experienced issues with Single Sign-On (SSO) via Microsoft. In specific situations, this can result in a 404 error during the login process. This issue is caused by a limitation on the maximum allowed URL or query string length within IIS.

By making a small configuration change in the web.config of the affected services, this problem can be resolved.

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Symptoms

• Logging in via Microsoft SSO occasionally fails

• The user encounters a 404 error during or immediately after the Microsoft login

• The issue does not occur consistently, but only for specific accounts or scenarios

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Cause

Microsoft SSO relies on redirects that include relatively long URLs and query strings. By default, IIS enforces a limited maximum length for these values. When this limit is exceeded, IIS returns a 404 error.

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Solution

By increasing the maximum allowed length for the URL and query string in IIS, Microsoft SSO can function correctly again.

Add the following configuration to the web.config of the relevant service(s):

The relevant services are:

• AppsService

• Platform

• Apps

<system.webServer>
  <security>
    <requestFiltering>
      <requestLimits maxUrl="16384" maxQueryString="8192" />
    </requestFiltering>
  </security>
</system.webServer>

Impact

• No functional impact on other parts of the application

• The change is safe and limited to request validation

• Recommended for all environments that use Microsoft SSO

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Need help?

If you need assistance applying this change, please contact our support department.

• [email protected]

Changelog

Version	Date	Change
1.0	Januari 22, 2026	Initial documentation version added.