Added "Enrollment fails because of issues with the service discovery"…

… to "Known issues"

memdocs/intune/enrollment/apple-account-driven-user-enrollment.md

@@ -152,6 +152,24 @@ If the Microsoft Authenticator app is on the device before enrollment begins, en
 
 To get around this issue, the device user must uninstall the Microsoft Authenticator app and restart enrollment.  
 
+### Enrollment fails because of issues with the service discovery
+If the service discovery mentioned in the [Prerequisites](#prerequisites) have not been configured correctly, users will notice the following error message:
+
+* Title: Sign-in Failed
+* Description: Your Apple ID does not support the expected services on this device. Contact your administrator to sign in.
+
+In order to solve this issue, make sure that your webserver is hosting the service discovery file with the content type set to `application/json`.
+You can validate that by running the following commands:
+```cmd
+   curl -I "https://contoso.com/.well-known/com.apple.remotemanagement"
+   ```
+
+```cmd
+   curl -I "https://contoso.com/.well-known/com.apple.remotemanagement?user-identifier=firstname.surname@contoso.com&model-family=iPhone"
+   ```
+
+Both of these commands should return `Content-Type: application/json`
+
 ## Next steps  
 * For an overview of supported Apple User Enrollment features and management actions in Microsoft Intune, see [Overview of Apple User Enrollment in Microsoft Intune](ios-user-enrollment-supported-actions.md).  
 * For more information about Apple User Enrollment, see [User Enrollment and MDM](https://support.apple.com/guide/deployment/user-enrollment-and-mdm-dep23db2037d/web) on the Apple support website.