Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires sonata-project/admin-bundle ^3.107.3 -> satisfiable by sonata-project/admin-bundle[3.107.3]. - sonata-project/admin-bundle 3.107.3 requires symfony/form ^4.4.12 -> found symfony/form[v4.4.12, ..., v4.4.48] but it conflicts with your root composer.json require ( ~4.2.0). Problem 2 - sonata-project/block-bundle 3.20.0 requires symfony/form ^4.3 -> found symfony/form[v4.3.0, ..., v4.4.48] but it conflicts with your root composer.json require ( ~4.2.0). - sonata-project/block-bundle[3.21.0, ..., 3.23.3] require symfony/form ^4.4 -> found symfony/form[v4.4.0, ..., v4.4.48] but it conflicts with your root composer.json require ( ~4.2.0). - Root composer.json requires sonata-project/block-bundle ^3.20 -> satisfiable by sonata-project/block-bundle[3.20.0, ..., 3.23.3].