Fatal error: Uncaught Error: Call to undefined function trailingslashit() in C:\xampp\htdocs\wordpress\wp-includes\class-wp-textdomain-registry.php:103
Stack trace:
#0 C:\xampp\htdocs\wordpress\wp-includes\l10n.php(784): WP_Textdomain_Registry->set('default', 'bg_BG', 'C:\\xampp\\htdocs...')
#1 C:\xampp\htdocs\wordpress\wp-includes\load.php(1401): load_textdomain('default', 'C:\\xampp\\htdocs...', 'bg_BG')
#2 C:\xampp\htdocs\wordpress\wp-includes\load.php(278): wp_load_translations_early()
#3 C:\xampp\htdocs\wordpress\wp-settings.php(74): wp_maintenance()
#4 C:\xampp\htdocs\wordpress\wp-config.php(100): require_once('C:\\xampp\\htdocs...')
#5 C:\xampp\htdocs\wordpress\wp-load.php(50): require_once('C:\\xampp\\htdocs...')
#6 C:\xampp\htdocs\wordpress\wp-blog-header.php(13): require_once('C:\\xampp\\htdocs...')
#7 C:\xampp\htdocs\wordpress\index.php(17): require('C:\\xampp\\htdocs...')
#8 {main}
thrown in C:\xampp\htdocs\wordpress\wp-includes\class-wp-textdomain-registry.php on line 103