Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires laravel/framework 12.x -> satisfiable by laravel/framework[12.x-dev (alias of dev-master)]. - laravel/framework dev-master requires nesbot/carbon ^3.8.4 -> found nesbot/carbon[dev-master, 3.8.4, 3.8.5, 3.x-dev (alias of dev-master)] but it conflicts with your root composer.json require (^2.70). - laravel/framework 12.x-dev is an alias of laravel/framework dev-master and thus requires it to be installed too.