WARNING(2): "require(/var/www/vhosts/shopintern.de/httpdocs/Gambio-Shop/gx3/vendor/composer/../symfony/polyfill-mbstring/bootstrap.php): failed to open stream: No such file or directory"
WARNING(2): "require(/var/www/vhosts/shopintern.de/httpdocs/Gambio-Shop/gx3/vendor/composer/../symfony/polyfill-mbstring/bootstrap.php): failed to open stream: No such file or directory"

Fatal error: require(): Failed opening required '/var/www/vhosts/shopintern.de/httpdocs/Gambio-Shop/gx3/vendor/composer/../symfony/polyfill-mbstring/bootstrap.php' (include_path='.:/opt/plesk/php/7.1/share/pear') in /var/www/vhosts/shopintern.de/httpdocs/Gambio-Shop/gx3/vendor/composer/autoload_real.php on line 66
COMPILE ERROR(64): "require(): Failed opening required '/var/www/vhosts/shopintern.de/httpdocs/Gambio-Shop/gx3/vendor/composer/../symfony/polyfill-mbstring/bootstrap.php' (include_path='.:/opt/plesk/php/7.1/share/pear')"