Updated from 1.7.1 to 1.7.3.3 causes
PHP Fatal error: Class ‘WPSEO_Options’ not found in /app/wp-content/plugins/wordpress-seo/wp-seo-main.php on line 216
This happend on heroku cedar-14 stack with official build pack (php5.6.6) after git push deployment. This means server was fresh started – so there is no way that old code was cached and my have caused the trouble.
Do you read me: There IS a bug in the code. Waiting for a fix.
Meanwhile: Rollback to 1.7.1. (that is slow but stable) hand hoping @yoast team will restore quality control and testing, soon…
BTW: I stopped using another big yoast plugin recently. Maybe I should seek for an lightwight SEO alternative, too… Suggestions welcome.