Warning: A link to the server could not be established in /var/www/deploy-client/current/libs/php7-mysql-shim/MySQL.php on line 25

Fatal error: Uncaught TypeError: Argument 2 passed to mysql_query() must be an instance of mysqli or null, boolean given, called in /var/www/deploy-client/current/includes/functions/database.php on line 180 and defined in /var/www/deploy-client/current/libs/php7-mysql-shim/overload.php:142 Stack trace: #0 /var/www/deploy-client/current/includes/functions/database.php(180): mysql_query('SELECT * FROM d...', false) #1 /var/www/deploy-client/current/includes/functions/database.php(215): tep_db_query('SELECT * FROM d...', 'db_reader', true) #2 /var/www/deploy-client/current/libs/Cache/MysqlQueryCache.php(154): tep_db_ro_query('SELECT * FROM d...') #3 /var/www/deploy-client/current/libs/Cache/MysqlQueryCache.php(78): Mystoreno\Cache\MysqlQueryCache->getFromMysql() #4 /var/www/deploy-client/current/libs/Cache/MysqlQueryCache.php(51): Mystoreno\Cache\MysqlQueryCache->executeCached() #5 /var/www/deploy-client/current/libs/Cache/MysqlQueryCache.php(203): Mystoreno\Cache\MysqlQueryCache->execute() #6 /var/www/deploy-client/current/ in /var/www/deploy-client/current/libs/php7-mysql-shim/overload.php on line 142