Database error encountered

Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /var/virtual/web/w0590/html/components/com_extcalendar/include/dblib.php on line 64

Warning: mysql_free_result(): supplied argument is not a valid MySQL result resource in /var/virtual/web/w0590/html/components/com_extcalendar/include/dblib.php on line 105
ExtCalendar critical error:
Unable to load template file template.html!