Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires drupal/acquia_cms_headless dev-develop -> satisfiable by drupal/acquia_cms_headless[dev-develop]. - drupal/acquia_cms_headless dev-develop requires drupal/next ^1.0 -> satisfiable by drupal/next[1.0.0-alpha1, ..., 1.6.3]. - drupal/next[1.0.0-alpha1, ..., 1.4.0] require drupal/core ^8.8 || ^9 -> found drupal/core[8.8.0-alpha1, ..., 8.9.x-dev, 9.0.0-alpha1, ..., 9.5.x-dev] but it conflicts with your root composer.json require (11.0.5). - drupal/next[1.0.x-dev, ..., 1.6.3] require drupal/core ^9 || ^10 -> found drupal/core[9.0.0-alpha1, ..., 9.5.x-dev, 10.0.0-alpha1, ..., 10.4.x-dev] but it conflicts with your root composer.json require (11.0.5). Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.