Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires acquia/acquia_cms * -> satisfiable by acquia/acquia_cms[dev-develop]. - acquia/acquia_cms dev-develop requires drupal/acquia_cms_site_studio dev-develop -> satisfiable by drupal/acquia_cms_site_studio[dev-develop]. - drupal/acquia_cms_common dev-develop requires drupal/acquia_starterkit_core ^1.0 -> found drupal/acquia_starterkit_core[dev-develop] but it does not match the constraint. - drupal/acquia_cms_site_studio dev-develop requires drupal/acquia_cms_common ^2.1.12 || ~3.2.12 || ^3.3.10 -> satisfiable by drupal/acquia_cms_common[3.x-dev (alias of dev-develop)]. - drupal/acquia_cms_common 3.x-dev is an alias of drupal/acquia_cms_common dev-develop and thus requires it to be installed too.