Fatal error: Uncaught Error: Call to undefined function wp_is_block_theme() in /wp-includes/post.php:359 Stack trace: #0 /wp-settings.php(394): create_initial_post_types() #1 /wp-config.php(90): require_once('/wp-settings.ph...') #2 /wp-load.php(50): require_once('/wp-config.php') #3 /wp-blog-header.php(13): require_once('/wp-load.php') #4 /index.php(17): require('/wp-blog-header...') #5 {main} thrown in /wp-includes/post.php on line 359