Fatal error: Uncaught Error: Call to undefined function trailingslashit() in /home/.sites/12/site1117/web/wp-includes/class-wp-textdomain-registry.php:103
Stack trace:
#0 /home/.sites/12/site1117/web/wp-includes/l10n.php(784): WP_Textdomain_Registry->set('default', 'de_DE', '/home/.sites/12...')
#1 /home/.sites/12/site1117/web/wp-includes/load.php(1401): load_textdomain('default', '/home/.sites/12...', 'de_DE')
#2 /home/.sites/12/site1117/web/wp-includes/load.php(278): wp_load_translations_early()
#3 /home/.sites/12/site1117/web/wp-settings.php(74): wp_maintenance()
#4 /home/.sites/12/site1117/web/wp-config.php(177): require_once('/home/.sites/12...')
#5 /home/.sites/12/site1117/web/wp-load.php(50): require_once('/home/.sites/12...')
#6 /home/.sites/12/site1117/web/wp-blog-header.php(13): require_once('/home/.sites/12...')
#7 /home/.sites/12/site1117/web/index.php(17): require('/home/.sites/12...')
#8 {main}
  thrown in /home/.sites/12/site1117/web/wp-includes/class-wp-textdomain-registry.php on line 103