Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires silverstripe/assets ^2.3 -> satisfiable by silverstripe/assets[2.3.0-beta1, 2.3.0-rc1, 2.3.x-dev, 2.x-dev]. - silverstripe/assets[2.3.0-beta1, ..., 2.x-dev] require silverstripe/framework ^5.1 -> satisfiable by silverstripe/framework[5.1.0-beta1, ..., 5.x-dev] from composer repo (https://repo.packagist.org) but silverstripe/framework is the root package and cannot be modified. See https://getcomposer.org/dep-on-root for details and assistance.