You'll receive this error if the source that you have provided in the widget code is not secure. Please check if your Freshdesk URL is secure (https) and replace the URL with the https in front.
If your Freshdesk URL is not secure, you could place a request for an SSL certificate at support@freshdesk.com. As a workaround kindly toggle off "use https" in the Admin -> Channels -> Feedback Form to prevent this error and until the SSL certificate is successfully processed.