Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires silverstripe/installer 5.0.x-dev -> satisfiable by silverstripe/installer[5.0.x-dev]. - silverstripe/installer 5.0.x-dev requires silverstripe/recipe-plugin 2.0.x-dev -> found silverstripe/recipe-plugin[2.0.x-dev] but it conflicts with your root composer.json require (^1). Problem 2 - silverstripe/recipe-cms 5.x-dev requires silverstripe/recipe-plugin 2.x-dev -> found silverstripe/recipe-plugin[2.x-dev] but it conflicts with your root composer.json require (^1). - silverstripe/recipe-cms 5.0.0-alpha1 requires silverstripe/recipe-plugin 2.0.0-alpha1 -> found silverstripe/recipe-plugin[2.0.0-alpha1] but it conflicts with your root composer.json require (^1). - silverstripe/recipe-cms 5.0.0-beta1 requires silverstripe/recipe-plugin ^2 -> found silverstripe/recipe-plugin[2.0.0-alpha1, 2.0.0, 2.0.x-dev, 2.x-dev] but it conflicts with your root composer.json require (^1). - silverstripe/recipe-cms[5.0.0-rc1, ..., 5.0.0] require silverstripe/recipe-plugin ~2.0.0@stable -> found silverstripe/recipe-plugin[2.0.0-alpha1, 2.0.0, 2.0.x-dev] but it conflicts with your root composer.json require (^1). - silverstripe/recipe-cms 5.0.x-dev requires silverstripe/recipe-plugin 2.0.x-dev -> found silverstripe/recipe-plugin[2.0.x-dev] but it conflicts with your root composer.json require (^1). - Root composer.json requires silverstripe/recipe-cms ^5 -> satisfiable by silverstripe/recipe-cms[5.0.0-alpha1, ..., 5.x-dev].