Fatal error: Uncaught Error: Call to undefined function is_main_site() in /home/pacs/ebe00/users/amabi/doms/abendmahlsbild.de/htdocs-ssl/wp-includes/update.php:959
Stack trace:
#0 {main}
thrown in /home/pacs/ebe00/users/amabi/doms/abendmahlsbild.de/htdocs-ssl/wp-includes/update.php on line 959