Fatal error: Uncaught Error: Non-static method YahooSession::requireSession() cannot be called statically in /var/www/html/demos/yahoo_oauth/yahoo_connect.php:16 Stack trace: #0 /var/www/html/demos/yahoo_oauth/index.php(2): include() #1 {main} thrown in /var/www/html/demos/yahoo_oauth/yahoo_connect.php on line 16