WordPress version: 3.4.2
WordPress SEO version: 18.104.22.168
I did this: Went to edit a post with a focus keyword
I expected the plugin to do this: Load the post and SEO meta box
Instead it did this: Fatal php error that Yoast_TextStatistics didn't exist at line 1055 in admin/class-metabox.php, this is because we disabled page analysis with the filter: "wpseo_use_page_analysis"
The fix for this is to carry over the filter check for the tab output and the tab link within an if conditional like other areas that check for the filter:
if ( apply_filters( 'wpseo_use_page_analysis', true ) === true )