How to fix ?
Symfony\Component\Debug\Exception\FatalErrorExceptionDeclaration of Doctrine\DBAL\Driver\PDOConnection::query() must be compatible with PDO::query(string $query, ?int $fetchMode = null, mixed …$fetchModeArgs)
#1 – I removed from composer.json the following line
"doctrine/dbal": "^2.10",
#2 – Run composer upgrade
#3 – Run composer upgrade
Voila Job Done !