Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires simplesamlphp/simplesamlphp 2.5.* -> satisfiable by simplesamlphp/simplesamlphp[v2.5.0, v2.5.1, v2.5.2]. - simplesamlphp/simplesamlphp v2.5.0 requires simplesamlphp/saml2 ~6.1 -> satisfiable by simplesamlphp/saml2[dev-master, v6.1.0, ..., v6.2.1] from composer repo (https://repo.packagist.org) but simplesamlphp/saml2 dev-feature/dom-migration-php84 is the root package and cannot be modified. See https://getcomposer.org/dep-on-root for details and assistance. - simplesamlphp/simplesamlphp[v2.5.1, ..., v2.5.2] require ext-fileinfo * -> it is missing from your system. Install or enable PHP's fileinfo extension. 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-fileinfo` to temporarily ignore these required extensions.