Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires simplesamlphp/simplesamlphp ~2.4.0 -> satisfiable by simplesamlphp/simplesamlphp[v2.4.0]. - simplesamlphp/simplesamlphp v2.4.0 requires simplesamlphp/saml2 ^5@dev -> found simplesamlphp/saml2[v5.0.0-alpha.1, ..., v5.0.0-alpha.21] but it does not match your minimum-stability.