Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires moneyphp/crypto-currencies dev-main -> satisfiable by moneyphp/crypto-currencies[dev-main]. - moneyphp/crypto-currencies dev-main requires php ~8.0.0 || ~8.1.0 || ~8.2.0 || ~8.3.0 -> your php version (8.4.0-dev) does not satisfy that requirement. Problem 2 - Root composer.json requires moneyphp/iso-currencies dev-master -> satisfiable by moneyphp/iso-currencies[dev-master]. - moneyphp/iso-currencies dev-master requires php ~8.1.0 || ~8.2.0 || ~8.3.0 -> your php version (8.4.0-dev) does not satisfy that requirement. Problem 3 - Root composer.json requires vimeo/psalm ~5.20.0 -> satisfiable by vimeo/psalm[5.20.0]. - vimeo/psalm 5.20.0 requires php ^7.4 || ~8.0.0 || ~8.1.0 || ~8.2.0 || ~8.3.0 -> your php version (8.4.0-dev) does not satisfy that requirement. Problem 4 - vimeo/psalm 5.20.0 requires php ^7.4 || ~8.0.0 || ~8.1.0 || ~8.2.0 || ~8.3.0 -> your php version (8.4.0-dev) does not satisfy that requirement. - 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[5.20.0]. - Root composer.json requires psalm/plugin-phpunit ^0.18.4 -> satisfiable by psalm/plugin-phpunit[0.18.4].