Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires sylius/sylius ^1.14 -> satisfiable by sylius/sylius[v1.14.0, v1.14.1, v1.14.2]. - sylius/sylius[v1.14.0, ..., v1.14.2] require league/flysystem-bundle ^2.4 -> found league/flysystem-bundle[2.4.0] but it conflicts with your root composer.json require (^3.3).