WordPress version: 3.4.1
WordPress SEO version: 1.2.5
The theme developer added WPSEO_frontend::metadesc(); to the theme's header.php. Since my client updates the SEO plugin himself a few days ago the following fatal error appeared:
Fatal error: Using $this when not in object context in /public_html/cms/wp-content/plugins/wordpress-seo/frontend/class-frontend.php on line 797
WPSEO_frontend::metadesc(); looks to be the problem, but I am not sure what to do next. If any one could show me the right direction where to look, that would be awesome.