Warning: require_once(/home/httpd/vhosts/xivix.ch/httpdocs/wp-includes/PHPMailer/PHPMailer.php): Failed to open stream: Permission denied in /home/httpd/vhosts/xivix.ch/httpdocs/wp-content/plugins/wp-mail-smtp/src/Core.php on line 902

Fatal error: Uncaught Error: Failed opening required '/home/httpd/vhosts/xivix.ch/httpdocs/wp-includes/PHPMailer/PHPMailer.php' (include_path='.:/usr/share/pear:/usr/share/php') in /home/httpd/vhosts/xivix.ch/httpdocs/wp-content/plugins/wp-mail-smtp/src/Core.php:902
Stack trace:
#0 /home/httpd/vhosts/xivix.ch/httpdocs/wp-content/plugins/wp-mail-smtp/src/Core.php(649): WPMailSMTP\Core->generate_mail_catcher(true)
#1 /home/httpd/vhosts/xivix.ch/httpdocs/wp-content/plugins/wp-mail-smtp/src/Core.php(634): WPMailSMTP\Core->replace_w_fake_phpmailer(NULL)
#2 /home/httpd/vhosts/xivix.ch/httpdocs/wp-includes/class-wp-hook.php(324): WPMailSMTP\Core->replace_phpmailer('')
#3 /home/httpd/vhosts/xivix.ch/httpdocs/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(Object(WPMailSMTP\Processor), Array)
#4 /home/httpd/vhosts/xivix.ch/httpdocs/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#5 /home/httpd/vhosts/xivix.ch/httpdocs/wp-settings.php(555): do_action('plugins_loaded')
#6 /home/httpd/vhosts/xivix.ch/httpdocs/wp-config.php(78): require_once('/home/httpd/vho...')
#7 /home/httpd/vhosts/xivix.ch/httpdocs/wp-load.php(50): require_once('/home/httpd/vho...')
#8 /home/httpd/vhosts/xivix.ch/httpdocs/wp-blog-header.php(13): require_once('/home/httpd/vho...')
#9 /home/httpd/vhosts/xivix.ch/httpdocs/index.php(17): require('/home/httpd/vho...')
#10 {main}
  thrown in /home/httpd/vhosts/xivix.ch/httpdocs/wp-content/plugins/wp-mail-smtp/src/Core.php on line 902