Your requirements could not be resolved to an installable set of packages. Problem 1 - silverstripe/cms[5.0.0-alpha1, ..., 5.x-dev] require php ^8.1 -> your php version (7.4; overridden via config.platform, actual: 7.4.33) does not satisfy that requirement. - silvershop/core 4.x-dev is an alias of silvershop/core dev-main and thus requires it to be installed too. - silvershop/core dev-main requires silverstripe/cms ^5 -> satisfiable by silverstripe/cms[5.0.0-alpha1, ..., 5.x-dev]. - Root composer.json requires silvershop/core ^4 -> satisfiable by silvershop/core[4.x-dev (alias of dev-main)].