"Provisional headers are shown" Error in Microsoft Edge Browser but works fine in Chrome browser

Question

I am using adal-angular.min-1.0.17.js for the authentication flow in my application. While acquiring a token using AuthenticationContext, I am encountering an issue specifically in the Microsoft Edge browser. The browser shows "Provisional headers are shown" during the token acquisition request.

The behavior is different in Google Chrome, where the entire authentication process completes successfully without any errors.

In Edge, the token is acquired successfully, but after redirection back to my web application, the page becomes stuck and does not load further. This issue started occurring after the Microsoft Edge update on 04-Dec-2025.

Could you please provide guidance, or let me know if this is a known issue with the recent Edge update or with ADAL compatibility?

Any help or suggestions would be greatly appreciated.

Answer 1

Hello. After signing in, does the app return to the exact same URL and route it started from, or does it navigate to a different route and depend on Angular to rebuild the session?

Answer 2

The issue you are experiencing with the "Provisional headers are shown" message in Microsoft Edge during the token acquisition process using adal-angular.min-1.0.17.js may be related to the way Edge handles requests and responses, especially after updates. This message typically indicates that the browser is not able to display the full headers of the request, which can happen due to various reasons including security settings or compatibility issues with the library being used.

Since you mentioned that the issue started occurring after the Microsoft Edge update on 04-Dec-2025, it is possible that this update introduced changes that affect how authentication flows work in Edge. Here are a few suggestions to troubleshoot and potentially resolve the issue:

1. Check Security Settings: Ensure that the security settings in Microsoft Edge are configured to allow pop-ups and third-party cookies, as these can affect the authentication flow.
2. Use Local Storage: If you are using session storage, consider configuring ADAL to use local storage instead, as session storage can be cleared during navigation.
3. Update ADAL Library: Check if there is a newer version of the ADAL library that may have addressed compatibility issues with recent browser updates.
4. Debugging: Use the developer tools in Edge to monitor network requests and console errors. This may provide more insight into what is happening during the token acquisition process.
5. Cross-Browser Testing: Since the process works fine in Chrome, it might be beneficial to implement feature detection or browser-specific handling in your application to ensure compatibility across different browsers.

If these steps do not resolve the issue, you may want to report the problem through the appropriate channels to Microsoft, as it could be a bug introduced in the latest update.

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References:

• Known issues on Internet Explorer and Microsoft Edge browsers (MSAL.js)
• Site compatibility-impacting changes coming to Microsoft Edge