Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires sylius/state-machine-abstraction ^1.0 -> satisfiable by sylius/state-machine-abstraction[v1.13.0, ..., v1.14.1]. - Root composer.json requires sylius/sylius ~2.0.0 -> satisfiable by sylius/sylius[v2.0.0, v2.0.1, v2.0.2]. - Only one of these can be installed: sylius/state-machine-abstraction[v1.13.0, ..., v1.14.1], sylius/sylius[v2.0.0, v2.0.1, v2.0.2]. sylius/sylius replaces sylius/state-machine-abstraction and thus cannot coexist with it.