Hard to clear the cache when you can't even get a login screen of the BO.
The latest error message suggests that there is some slashes problem because of migrating from Windows to Linux. I have added some linefeeds for readability.:
PHP Fatal error: Uncaught Symfony\\Component\\Config\\Exception\\FileLocatorFileNotFoundException:
The file "/var/www/html/ps175\\app/config/routing.yml" does not exist.
in /var/www/html/ps175/vendor/symfony/symfony/src/Symfony/Component/Config/FileLocator.php:44\nStack
trace:\n#0 /var/www/html/ps175/vendor/symfony/symfony/src/Symfony/Component/HttpKernel/Config/FileLocator.php(52):
Symfony\\Component\\Config\\FileLocator->locate('/var/www/html/_...', NULL, true)\n#1
/var/www/html/ps175/vendor/symfony/symfony/src/Symfony/Component/Routing/Loader/YamlFileLoader.php(46):
Symfony\\Component\\HttpKernel\\Config\\FileLocator->locate('/var/www/html/_...')\n#2
/var/www/html/ps175/vendor/symfony/symfony/src/Symfony/Component/Config/Loader/DelegatingLoader.php(40):
Symfony\\Component\\Routing\\Loader\\YamlFileLoader->load('/var/www/html/_...', NULL)\n#3
/var/www/html/ps175/vendor/symfony/symfony/src/Symfony/Bundle/FrameworkBundle/Routing/DelegatingLoader.php(70):
Symfony\\Component\\Config\\Loader\\DelegatingLoader->load('/var/www/html/_...', NULL in
/var/www/html/ps175/vendor/twig/twig/lib/Twig/Loader/Filesystem.php on line 101
It puzzles me why people still struggle with slashes. Windows works perfectly when you use forward slashes.