Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires react-parallel/react-parallel ^2@dev -> satisfiable by react-parallel/react-parallel[2.0.0, 2.1.0, 2.x-dev]. - Root composer.json requires react/filesystem 0.1.2@dev -> satisfiable by react/filesystem[v0.1.2]. - Root composer.json requires wyrihaximus/async-test-utilities ^8.0.5 -> satisfiable by wyrihaximus/async-test-utilities[8.0.5]. - react-parallel/event-loop 2.0.0 requires react/promise ^2.11 || ^3.2 -> satisfiable by react/promise[v2.11.0, 2.x-dev, v3.2.0, v3.3.0, 3.x-dev]. - react-parallel/event-loop 2.1.0 requires php ^8.3 -> your php version (8.2.13; overridden via config.platform, actual: 8.5.1) does not satisfy that requirement. - react-parallel/react-parallel 2.1.0 requires php ^8.3 -> your php version (8.2.13; overridden via config.platform, actual: 8.5.1) does not satisfy that requirement. - react-parallel/event-loop 2.x-dev requires php ^8.4 -> your php version (8.2.13; overridden via config.platform, actual: 8.5.1) does not satisfy that requirement. - react-parallel/react-parallel 2.x-dev requires php ^8.4 -> your php version (8.2.13; overridden via config.platform, actual: 8.5.1) does not satisfy that requirement. - react-parallel/react-parallel 2.0.0 requires react-parallel/event-loop ^2.0.0 -> satisfiable by react-parallel/event-loop[2.0.0, 2.1.0, 2.x-dev]. - react/filesystem v0.1.2 requires react/promise ~2.2 -> satisfiable by react/promise[v2.2.0, ..., 2.x-dev]. - Conclusion: don't install react/promise v2.11.0 (conflict analysis result) - Conclusion: don't install react/promise v3.2.0 (conflict analysis result) - You can only install one version of a package, so only one of these can be installed: react/promise[v1.0.0, ..., 1.x-dev, v2.0.0, ..., 2.x-dev, v3.0.0, ..., 3.x-dev]. Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.