Your lock file does not contain a compatible set of packages. Please run composer update. Problem 1 - vimeo/psalm is locked to version 5.x-dev and an update of this package was not requested. - vimeo/psalm 5.x-dev requires php ^7.4 || ~8.0.0 || ~8.1.0 || ~8.2.0 || ~8.3.0 -> your php version (8.4.2) does not satisfy that requirement. Problem 2 - psalm/plugin-phpunit is locked to version 0.18.4 and an update of this package was not requested. - psalm/plugin-phpunit 0.18.4 requires vimeo/psalm dev-master || dev-4.x || ^4.7.1 || ^5@beta || ^5.0 -> satisfiable by vimeo/psalm[5.x-dev]. - vimeo/psalm 5.x-dev requires php ^7.4 || ~8.0.0 || ~8.1.0 || ~8.2.0 || ~8.3.0 -> your php version (8.4.2) does not satisfy that requirement.