Admin URL Access Issue

1. **Check the Custom Admin URL Settings**: Make sure that the plugin or code you're using to change the `wp-admin` URL is configured correctly. If you’re using a specific plugin for this, check its documentation for any specific settings related to user permissions or URL handling.

2. **Redirect Unauthorized Access**: Ensure that your new admin URL handles unauthorized access appropriately. If users try to access the `users.php` page without being logged in, they should be redirected to the login page. You might need to add custom code to handle redirection. For example:

function custom_admin_redirect() {
       if ( strpos( $_SERVER['REQUEST_URI'], 'focus-admin' ) !== false && !is_user_logged_in() ) {
           wp_redirect( wp_login_url( $_SERVER['REQUEST_URI'] ) );
           exit;
       }
   }
   add_action( 'admin_init', 'custom_admin_redirect' );

3. **Test with Default Permalinks**: Sometimes, custom permalink structures can interfere with URL handling. Temporarily switch to default permalinks in the WordPress settings to see if that resolves the issue. If it does, you may need to reconfigure your custom URLs.

4. **Check for Plugin Conflicts**: Deactivate other plugins one by one to check if there’s a conflict with your user management or admin URL change. Some security or redirection plugins might prevent access.

5. **Review `.htaccess` File**: If you’re using Apache, make sure your `.htaccess` file is correctly set up to handle the new URL structure. You may need to add or update rules to redirect requests appropriately.

6. **Clear Cache**: If you're using caching plugins (like W3Speedster or WP Super Cache), clear the cache after making changes to ensure you're seeing the most up-to-date version of your site.

7. **Error Logs**: Check your server error logs for any specific errors when trying to access that URL. This might give you clues about what’s going wrong.

After going through these steps, try accessing the modified admin URL again to see if it works as expected. If you still encounter issues, providing more details about the specific setup or plugins you're using might help narrow down the problem further.