Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires vimeo/psalm ^5.26.1 -> satisfiable by vimeo/psalm[5.26.1]. - vimeo/psalm 5.26.1 requires php ^7.4 || ~8.0.0 || ~8.1.0 || ~8.2.0 || ~8.3.0 -> your php version (8.4.3) does not satisfy that requirement. Problem 2 - Root composer.json requires roave/infection-static-analysis-plugin ^1.35 -> satisfiable by roave/infection-static-analysis-plugin[1.35.0, 1.36.0]. - roave/infection-static-analysis-plugin 1.35.0 requires php ~8.1.0 || ~8.2.0 || ~8.3.0 -> your php version (8.4.3) does not satisfy that requirement. - roave/infection-static-analysis-plugin 1.36.0 requires vimeo/psalm ^6.0 -> found vimeo/psalm[6.0.0] but it conflicts with your root composer.json require (^5.26.1).