Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires eliashaeussler/rector-config ^3.0 -> satisfiable by eliashaeussler/rector-config[3.0.0, ..., 3.0.4]. - Root composer.json requires phpstan/phpstan-phpunit ^2.0 -> satisfiable by phpstan/phpstan-phpunit[2.0.0, 2.0.1]. - eliashaeussler/rector-config[3.0.0, ..., 3.0.3] require php ~8.1.0 || ~8.2.0 || ~8.3.0 -> your php version (8.4.1) does not satisfy that requirement. - eliashaeussler/rector-config 3.0.4 requires rector/rector ^1.2.9 -> satisfiable by rector/rector[1.2.9, 1.2.10]. - phpstan/phpstan-phpunit[2.0.0, ..., 2.0.1] require phpstan/phpstan ^2.0 -> satisfiable by phpstan/phpstan[2.0.0, 2.0.1, 2.0.2, 2.0.3]. - rector/rector[1.2.6, ..., 1.2.10] require phpstan/phpstan ^1.12.5 -> satisfiable by phpstan/phpstan[1.12.5, ..., 1.12.12]. - You can only install one version of a package, so only one of these can be installed: phpstan/phpstan[1.7.15, ..., 1.12.12, 2.0.0, 2.0.1, 2.0.2, 2.0.3]. Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.