Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, function "wp_print_speculation_rules" not found or invalid function name in C:\xampp\htdocs\wp-includes\class-wp-hook.php:324
Stack trace:
#0 C:\xampp\htdocs\wp-includes\class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array)
#1 C:\xampp\htdocs\wp-includes\plugin.php(517): WP_Hook->do_action(Array)
#2 C:\xampp\htdocs\wp-includes\general-template.php(3208): do_action('wp_footer')
#3 C:\xampp\htdocs\wp-includes\template-canvas.php(25): wp_footer()
#4 C:\xampp\htdocs\wp-includes\template-loader.php(106): include('C:\\xampp\\htdocs...')
#5 C:\xampp\htdocs\wp-blog-header.php(19): require_once('C:\\xampp\\htdocs...')
#6 C:\xampp\htdocs\index.php(17): require('C:\\xampp\\htdocs...')
#7 {main}
thrown in C:\xampp\htdocs\wp-includes\class-wp-hook.php on line 324