SharePoint server 2019 Site Still Prompts for Authentication Despite Enabling Anonymous Access

Question

I am working with SharePoint Server 2019 and have encountered an issue where the site continues to prompt for authentication even after configuring it to allow anonymous access.

When it prompt authentication on our default page, and if we cancel it then the site is going smooth, without any authentication error. But only on initial it raising.

Here are the steps I have already completed:

IIS Settings:

Verified that Anonymous Authentication is enabled for the SharePoint web application in IIS Manager.

Confirmed that Windows Authentication is also enabled.

Web Application Authentication Providers:

 Navigated to Central Administration > Manage web applications.

 Selected the affected web application and clicked on Authentication Providers.

 Ensured that the appropriate zone (e.g., Default) is configured to allow anonymous access.

       Anonymous Access in SharePoint Settings:

          Opened the affected site collection.

          Went to Site Settings > Site Permissions.
``` Verified that Anonymous Access is set to allow the desired permissions (e.g., entire site).

Despite these configurations, the site still prompts users for authentication.

Answer 1

Hi @Arunachalam J，

Here is the checklist for troubleshooting keep getting login prompt:

1. Anonymous access must be turned on both at the Web Application level and at the SharePoint site level. Double-check your settings with How to Enable Anonymous Access in SharePoint
2. On publishing sites, try disabling the feature “Limited-access user permission lockdown mode” at the site collection level.
3.  If the default home page, say default.aspx page is not published & approved, users get a login prompt!
4. If any referenced resources like images, scripts, CSS files, etc from other libraries require authentication – You’ll get an authentication prompt! E.g. You may have a CSS style sheet from a library, which may not allow anonymous access! Check the permission for the specific library and grant anonymous users to “read” the content.
5. Navigate to the IIS Virtual directory on the File system using Windows Explorer, Go to the Security tab, make sure that “Everyone” has Read privileges. If not, add it!
6. In IIS, expand your web application, click on “Authentications”, make sure “Anonymous Authentication” is enabled.
7. In SharePoint Central Administration >> Application Management >> Manage Web applications, select the web application and click on “Anonymous Policy”. Make sure that “None – No Policy” is selected.
8. If you enabled Anonymous access at list/library level: Delete unique permissions once, stop inheriting permissions and then grant anonymous access again.

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