add toc

Author: genlin

support/entra/entra-id/app-integration/troubleshoot-wif10201-no-valid key-securitytoken-mvc.md

@@ -8,15 +8,15 @@ ms.topic: troubleshooting-general
 ms.date: 02/05/2025
 ms.custom: sap:Issues Signing In to Applications
 ---
-# WIF10201: No valid key mapping found for securityToken in ASP.NET MVC application
+# WIF10201: No valid key mapping found for securityToken in ASP.NET application
 
 This article provides guidance for troubleshooting an authentication issue in an ASP.NET MVC application that uses both [WS-Federation](https://github.com/Azure-Samples/active-directory-dotnet-webapp-wsfederation) OWIN middleware and [Windows Identity Foundation](../../../windows-server/user-profiles-and-logon/windows-identity-foundation.md) (WIF) to authenticate to Microsoft Entra ID.
 
 ## Symptom
 
-The ASP.NET MVC application was working previously; however, the following error is now occurring without any changes to the application.
+The ASP.NET MVC application was working previously. However, the following error is now occurring without any changes to the application.
 
-```dotnetcli
+```dotnecli
 Error Details:
 Server Error in ‘/’ Application.
 WIF10201: No valid key mapping found for securityToken: ‘System.IdentityModel.Tokens.X509SecurityToken’ and issuer: ‘https://sts.windows.net/<Directory ID>/’.
@@ -26,7 +26,7 @@ Description: An unhandled exception occurred during the execution of the current
 Exception Details: System.IdentityModel.Tokens.SecurityTokenValidationException: WIF10201: No valid key mapping found for securityToken: ‘System.IdentityModel.Tokens.X509SecurityToken’ and issuer: ‘https://sts.windows.net/<Directory ID>/’.
 ```
 
-## Cause 
+## Cause
 
 Windows Identity Foundation uses the certificate thumbprint(s) in the web.config file (shown below) to verify the signature of the token returned from THE Entra ID upon successful sign in.
 

support/entra/entra-id/toc.yml

@@ -51,6 +51,8 @@
     items:
       - name: IDX10501 Error in ASP.NET Core with Azure B2C Custom Policy
         href: app-integration/troubleshoot-error-idx10501-aspnet-b2c.md
+      - name: WIF10201 No valid key mapping found
+        href: app-integration/troubleshoot-wif10201-no-valid key-securitytoken-mvc.md
 
   - name: Troubleshoot adding apps
     href: app-integration/troubleshoot-adding-apps.md