Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires platine-php/lang 1.0.x-dev (exact version match), found platine-php/lang[dev-develop] but it does not match the constraint. Problem 2 - Root composer.json requires platine-php/dev 1.0.x-dev (exact version match), found platine-php/dev[dev-develop] but it does not match the constraint.