Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires symfony/http-client-contracts ^6 || ^7, found symfony/http-client-contracts[dev-main, v1.1.1, ..., v1.10.0, v2.0.0, ..., 2.5.x-dev, v3.0.0, ..., 3.5.x-dev (alias of dev-main)] but it does not match the constraint. Problem 2 - contao/core-bundle[5.3.0, ..., 5.3.12] require symfony/http-client-contracts ^3.1 -> found symfony/http-client-contracts[v3.1.0, ..., v3.5.0] but it conflicts with your root composer.json require (^6 || ^7). - Root composer.json requires contao/core-bundle ^5.3 -> satisfiable by contao/core-bundle[5.3.0, ..., 5.3.12].