Updated the 3.3.1 on another site and had a similar problem on the PHP error.
PHP Fatal error: Class ‘WPSEO_Metabox_Editor’ not found in C:\inetpub\vhosts\sanclementedonor.redfontmarketing.com\httpdocs\wp-content\plugins\wordpress-seo\admin\metabox\class-metabox.php on line 42
There is another class file called class-metabox-editor.php in the same folder so i’m not sure what’s wrong. I restarted the site and the error no longer appears. Very strange bug…not sure why the call to that file would fail until the site was restarted.
After enabling PHP error logging, restarting the site, and re-activating the Yoast plugin I could not recreate the Yoast problem.
