Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires platine-php/lang ^1.0 -> satisfiable by platine-php/lang[v1.0.0]. - platine-php/lang v1.0.0 requires ext-gettext * -> it is missing from your system. Install or enable PHP's gettext extension. Problem 2 - platine-php/lang v1.0.0 requires ext-gettext * -> it is missing from your system. Install or enable PHP's gettext extension. - platine-php/validator v1.0.0 requires platine-php/lang ^1.0 -> satisfiable by platine-php/lang[v1.0.0]. - Root composer.json requires platine-php/validator ^1.0 -> satisfiable by platine-php/validator[v1.0.0]. To enable extensions, verify that they are enabled in your .ini files: - C:\tools\php\php.ini You can also run `php --ini` in a terminal to see which files are used by PHP in CLI mode. Alternatively, you can run Composer with `--ignore-platform-req=ext-gettext` to temporarily ignore these required extensions.