Fatal error: Uncaught Error: Call to undefined function wp_theme_has_theme_json() in /wp-content/plugins/cartflows/modules/gutenberg/classes/class-cartflows-init-blocks.php:78 Stack trace: #0 /wp-content/plugins/cartflows/modules/gutenberg/classes/class-cartflows-init-blocks.php(42): Cartflows_Init_Blocks->__construct() #1 /wp-content/plugins/cartflows/modules/gutenberg/classes/class-cartflows-init-blocks.php(587): Cartflows_Init_Blocks::get_instance() #2 /wp-content/plugins/cartflows/modules/gutenberg/classes/class-cartflows-block-loader.php(64): require_once('/wp-content/plu...') #3 /wp-content/plugins/cartflows/modules/gutenberg/classes/class-cartflows-block-loader.php(44): Cartflows_Block_Loader->load_plugin() #4 /wp-content/plugins/cartflows/modules/gutenberg/classes/class-cartflows-block-loader.php(31): Cartflows_Block_Loader->__construct() #5 /wp-content/plugins/cartflows/modules/gutenberg/classes/class-cartflows-block-loader.php(76): Cartflows_Block_Loader::get_instance() #6 /wp-content/plugins/cartflows/classes/c in /wp-content/plugins/cartflows/modules/gutenberg/classes/class-cartflows-init-blocks.php on line 78