Warning: count(): Parameter must be an array or an object that implements Countable in system/cache/config/config.php on line 2747

#0 system/cache/config/config.php(2747): __error()
#1 system/modules/core/library/Contao/Config.php(130): include('/var/www/vhosts...')
#2 system/modules/core/library/Contao/Config.php(108): Contao\Config->initialize()
#3 system/initialize.php(162): Contao\Config::getInstance()
#4 index.php(16): require('/var/www/vhosts...')
#5 {main}

Fatal error: Cannot use 'String' as class name as it is reserved in /var/www/vhosts/dav-belgien.be/public_html/live/system/modules/core/library/Contao/String.php on line 28