Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires friendsofphp/php-cs-fixer ^2.16 -> satisfiable by friendsofphp/php-cs-fixer[v2.16.0, ..., v2.19.3]. - Root composer.json requires roave/backward-compatibility-check * -> satisfiable by roave/backward-compatibility-check[1.0.0, ..., 1.1.1, 2.0.0, 2.1.0, 3.0.0, 4.0.0, ..., 4.4.0, 5.0.0, 6.0.0, ..., 6.4.0, 7.0.0, ..., 7.4.0, 8.0.0, ..., 8.19.0]. - friendsofphp/php-cs-fixer[v2.16.0, ..., v2.16.10] require php ^5.6 || ^7.0 -> your php version (8.4.18) does not satisfy that requirement. - friendsofphp/php-cs-fixer v2.16.6 requires php ^7.0 -> your php version (8.4.18) does not satisfy that requirement. - friendsofphp/php-cs-fixer v2.16.7 requires php ^7.1 -> your php version (8.4.18) does not satisfy that requirement. - friendsofphp/php-cs-fixer[v2.17.0, ..., v2.19.3] require symfony/process ^3.0 || ^4.0 || ^5.0 -> satisfiable by symfony/process[v5.4.51]. - Conclusion: don't install symfony/process v5.4.51 (conflict analysis result)