Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires symfony/security-guard ^5.4 -> satisfiable by symfony/security-guard[v5.4.0-BETA1, ..., 5.4.x-dev]. - symfony/security-guard v5.4.0-BETA1 requires symfony/security-core ^5.0|^6.0 -> found symfony/security-core[v5.0.0-BETA1, ..., 5.4.x-dev, v6.0.0-BETA1, ..., 6.4.x-dev] but these were not loaded, likely because it conflicts with another require. - symfony/security-guard[v5.4.0-RC1, ..., 5.4.x-dev] require symfony/security-core ^5.0 -> found symfony/security-core[v5.0.0-BETA1, ..., 5.4.x-dev] but these were not loaded, likely because it conflicts with another require.