Error with <a href='https://sub.example.com'>https://sub.example.com</a>
<p>exception = HTTPSConnectionPool(host='sub.example.com', port=443): Max retries exceeded with url: / (Caused by NameResolutionError("HTTPSConnection(host='sub.example.com', port=443): Failed to resolve 'sub.example.com' ([Errno -5] No address associated with hostname)"))