I had bad luck with 3 freelancers and now I have to get back into it. I used to work on osCommerce back in the day but my knowledge around Magento is very limited.
Right now I have to change all shop and server credentials. I got all done but when I change the SQL DB user and password in Plesk and in local.xml, I get:
SQLSTATE  Access denied for user 'xxxxxxxx'@'localhost' (using password: YES)
#0 /var/www/vhosts/feisol.net/httpdocs/lib/Zend/Db/Adapter/Pdo/Mysql.php(111): Zend_Db_Adapter_Pdo_Abstract->_connect()
#1 /var/www/vhosts/feisol.net/httpdocs/lib/Varien/Db/Adapter/Pdo/Mysql.php(320): Zend_Db_Adapter_Pdo_Mysql->_connect()
Since I can't access the backend, I deleted via FTP the cache under var/cache. This worked for the test shop under a sub domain, but the life shop still comes back with the 'access denied' error message.
I read somewhere that I also need to start the compiler. Is that correct? How can I do that via SSH? Any other suggestions?