Fatal error: Uncaught Error: Call to undefined function trailingslashit() in /home/httpd/vhosts/uska.ch/httpdocs/wp-includes/class-wp-textdomain-registry.php:103
Stack trace:
#0 /home/httpd/vhosts/uska.ch/httpdocs/wp-includes/l10n.php(784): WP_Textdomain_Registry->set('default', 'de_DE', '/home/httpd/vho...')
#1 /home/httpd/vhosts/uska.ch/httpdocs/wp-includes/load.php(1401): load_textdomain('default', '/home/httpd/vho...', 'de_DE')
#2 /home/httpd/vhosts/uska.ch/httpdocs/wp-includes/load.php(278): wp_load_translations_early()
#3 /home/httpd/vhosts/uska.ch/httpdocs/wp-settings.php(74): wp_maintenance()
#4 /home/httpd/vhosts/uska.ch/httpdocs/wp-config.php(97): require_once('/home/httpd/vho...')
#5 /home/httpd/vhosts/uska.ch/httpdocs/wp-load.php(50): require_once('/home/httpd/vho...')
#6 /home/httpd/vhosts/uska.ch/httpdocs/wp-blog-header.php(13): require_once('/home/httpd/vho...')
#7 /home/httpd/vhosts/uska.ch/httpdocs/index.php(17): require('/home/httpd/vho...')
#8 {main}
  thrown in /home/httpd/vhosts/uska.ch/httpdocs/wp-includes/class-wp-textdomain-registry.php on line 103

Fatal error: Uncaught Error: Call to undefined function wp_cache_get() in /home/httpd/vhosts/uska.ch/httpdocs/wp-includes/option.php:165
Stack trace:
#0 /home/httpd/vhosts/uska.ch/httpdocs/wp-includes/l10n.php(63): get_option('WPLANG')
#1 /home/httpd/vhosts/uska.ch/httpdocs/wp-includes/l10n.php(139): get_locale()
#2 /home/httpd/vhosts/uska.ch/httpdocs/wp-includes/l10n.php(866): determine_locale()
#3 /home/httpd/vhosts/uska.ch/httpdocs/wp-includes/class-wp-fatal-error-handler.php(47): load_default_textdomain()
#4 [internal function]: WP_Fatal_Error_Handler->handle()
#5 {main}
  thrown in /home/httpd/vhosts/uska.ch/httpdocs/wp-includes/option.php on line 165