Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires sylius/sylius ^1.12 -> satisfiable by sylius/sylius[v1.12.0, ..., v1.14.0]. - sylius/sylius[v1.12.0, ..., v1.14.0] require league/flysystem-bundle ^2.4 -> found league/flysystem-bundle[2.4.0] but it conflicts with your root composer.json require (^3.3).