Windows Authentication in IIS Express prompts credentials endlessly

Question

Windows Authentication in IIS Express prompts credentials endlessly

Croaker 5

I am trying to set up Windows Authentication for a .NET Framework 4.7.2 MVC application. When I run the app in Visual Studio (IIS Express), the browser (Chrome or Edge) prompts repeatedly for my credentials but never accepts (lets me view the page) or rejects them (shows a forbidden message etc.).

I have set the authentication mode to Windows in the web.config. And enabled Windows Auth and disabled Anonymous Auth in the project properties pane. How can I get it to evaluate the credentials properly?

Lan Huang-MSFT 30,191 Reputation points Microsoft External Staff

2023-12-22T06:59:10.6433333+00:00

Hi @Croaker,

If an authenticated user cannot read a folder in your web application that contains static content, it will authenticate you and then deny access. This can be resolved by granting local_Machine\Authenicated_Users access to the required resources.

You can try adding Authenticated_users to the IIS_IUSRS group, or grant any authenticated user permissions to all files and folders available to the IIS_IUSRs group.

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Lan Huang-MSFT 30,191 Reputation points Microsoft External Staff

2023-12-22T06:59:10.6433333+00:00

Hi @Croaker,

If an authenticated user cannot read a folder in your web application that contains static content, it will authenticate you and then deny access. This can be resolved by granting local_Machine\Authenicated_Users access to the required resources.

You can try adding Authenticated_users to the IIS_IUSRS group, or grant any authenticated user permissions to all files and folders available to the IIS_IUSRs group.

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Windows Authentication in IIS Express prompts credentials endlessly

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