Hello,
when saving articles in WordPress (with activated WordPress SEO Plugin) you have to be lucky to get saved documents. In 3 of 10 cases an HTTP 500 Error comes up - you have to go back to the article, make your changes AGAIN and again have to be lucky that saving works. :-/ In the server-logfile you can find this error then (I edited my URLs with xxxxxxx as you can see):
PHP Fatal error: Call to undefined function get_sample_permalink() in /is/htdocs/xxxxx_xxxxxxxx/www.xxxxxxxxxx.de/htdocs/wp-content/plugins/wordpress-seo/admin/class-metabox.php on line 1053, referer: http://www.xxxxxxxxxxxxx.de/wp-admin/post.php?post=1669&action=edit
Could you fix that problem? I found another thread about this, but it is 6 months old and still has no answers!
Hope for help.