Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires larastan/larastan ^v3.0.2 -> satisfiable by larastan/larastan[v3.0.2, 3.x-dev]. - Root composer.json requires pestphp/pest-plugin-laravel ^v2.4.0 -> satisfiable by pestphp/pest-plugin-laravel[v2.4.0, 2.x-dev]. - larastan/larastan[v3.0.2, ..., 3.x-dev] require illuminate/contracts ^11.15.0 -> satisfiable by illuminate/contracts[v11.15.0, ..., 11.x-dev]. - Conclusion: don't install illuminate/contracts v11.34.2 (conflict analysis result)