Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires sylius/calendar ^0.5.0 -> satisfiable by sylius/calendar[v0.5.0]. - sylius/calendar v0.5.0 requires symfony/framework-bundle ^5.4 || ^6.0 -> found symfony/framework-bundle[v5.4.0, ..., v5.4.45, v6.0.0, ..., v6.4.13] but these were not loaded, likely because it conflicts with another require. Problem 2 - Root composer.json requires sylius/state-machine-abstraction ^1.0 -> satisfiable by sylius/state-machine-abstraction[v1.13.0, ..., v1.14.1]. - sylius/state-machine-abstraction[v1.13.0, ..., v1.14.1] require php ^8.1 -> your php version (8.0.30) does not satisfy that requirement. Problem 3 - Root composer.json requires sylius/sylius ~1.11.0 -> satisfiable by sylius/sylius[v1.11.0, ..., v1.11.15]. - sylius/sylius[v1.11.0, ..., v1.11.15] require sylius/calendar ^0.3 -> found sylius/calendar[v0.3.0] but it conflicts with your root composer.json require (^0.5.0).