Warning: DOMDocument::loadHTMLFile(): SSL operation failed with code 1. OpenSSL Error messages: error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed in C:\xampp\apps\joomla\htdocs\calendar\clinic_calendar.php on line 8

Warning: DOMDocument::loadHTMLFile(): Failed to enable crypto in C:\xampp\apps\joomla\htdocs\calendar\clinic_calendar.php on line 8

Warning: DOMDocument::loadHTMLFile(https://calendar.google.com/calendar/embed?showTitle=0&showPrint=0&showTz=0&height=600&wkst=1&bgcolor=%23FFFFFF&src=g569fr33jsrg2f28tqvjank04k%40group.calendar.google.com&color=%23182C57&src=en.usa%23holiday%40group.v.calendar.google.com&color=%23125A12&ctz=America%2FChicago): failed to open stream: operation failed in C:\xampp\apps\joomla\htdocs\calendar\clinic_calendar.php on line 8

Warning: DOMDocument::loadHTMLFile(): I/O warning : failed to load external entity "https://calendar.google.com/calendar/embed?showTitle=0&showPrint=0&showTz=0&height=600&wkst=1&bgcolor=%23FFFFFF&src=g569fr33jsrg2f28tqvjank04k%40group.calendar.google.com&color=%23182C57&src=en.usa%23holiday%40group.v.calendar.google.com&color=%23125A12&ctz=America%2FChicago" in C:\xampp\apps\joomla\htdocs\calendar\clinic_calendar.php on line 8

Fatal error: Call to a member function getAttribute() on null in C:\xampp\apps\joomla\htdocs\calendar\clinic_calendar.php on line 11