Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires simplesamlphp/saml2 ~5.0.3 -> satisfiable by simplesamlphp/saml2[v5.0.3, v5.0.4]. - simplesamlphp/saml2[v5.0.3, ..., v5.0.4] require simplesamlphp/assert ~1.8.1 -> found simplesamlphp/assert[v1.8.1, v1.8.2, v1.8.3] but it conflicts with your root composer.json require (~1.9.0). Problem 2 - Root composer.json requires simplesamlphp/assert ~1.9.0 -> satisfiable by simplesamlphp/assert[v1.9.0, v1.9.1]. - simplesamlphp/assert[v1.9.0, ..., v1.9.1] require php ^8.2 -> your php version (8.1.33) does not satisfy that requirement.