I documented the error yesterday here
http://ww.wp.xz.cn/support/topic/plugin-wordpress-seo-by-yoast-1284-mapped-site-admin-broken
Issue seems to be with the get_option( ‘wpseo’ ) at the start of maybe_upgrade() function in class-admin.php. It should be returning a nice array like this (as per parent site) : Array ( [disableadvanced_meta] => on [version] => 1.2.8.4 [tracking_popup] => done [yoast_tracking] => off [ignore_tour] => ignore ). Instead, for child mapped site, we get only : 1pseo_social. Development version has the same issue.
I also offered a temp code fix to get you back going with 1.2.8.4 or the dev version.
Quick hack: in class-admin.php, comment out line 321, and hardcode the version:
function maybe_upgrade() {
$options = get_option( 'wpseo' );
//$current_version = isset( $options['version'] ) ? $options['version'] : 0;
$current_version = '1.2.8.4';
…
Obviously not the best idea … since the array is used in more places. Might get you by until Joost pushes a fix.
