Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires orchestra/testbench 10.* -> satisfiable by orchestra/testbench[v10.0.0, 10.x-dev]. - orchestra/testbench[v10.0.0, ..., 10.x-dev] require phpunit/phpunit ^11.5.3 -> found phpunit/phpunit[11.5.3, ..., 11.5.x-dev] but it conflicts with your root composer.json require (^9.5 || ^10.5). Problem 2 - Root composer.json requires illuminate/support ^9.0 || ^10.0 || ^11.0 -> satisfiable by illuminate/support[v9.0.0-beta.1, ..., 9.x-dev, v10.0.0, ..., 10.x-dev, v11.0.0, ..., 11.x-dev]. - Root composer.json requires laravel/framework 12.* -> satisfiable by laravel/framework[v12.0.0, v12.0.1, 12.x-dev]. - illuminate/support[v9.33.0, ..., 9.x-dev, v10.0.0, ..., v10.16.1] require nesbot/carbon ^2.62.1 -> found nesbot/carbon[2.62.1, ..., 2.x-dev] but it conflicts with your root composer.json require (3.*). - illuminate/support[v10.17.0, ..., 10.x-dev] require nesbot/carbon ^2.67 -> found nesbot/carbon[2.67.0, ..., 2.x-dev] but it conflicts with your root composer.json require (3.*). - illuminate/support[v9.0.0-beta.1, ..., v9.32.0] require nesbot/carbon ^2.53.1 -> found nesbot/carbon[2.53.1, ..., 2.x-dev] but it conflicts with your root composer.json require (3.*). - Conclusion: don't install illuminate/support v11.0.0 (conflict analysis result) - Conclusion: don't install illuminate/support v11.34.0 (conflict analysis result) - Only one of these can be installed: laravel/framework[v12.0.0, v12.0.1, 12.x-dev], illuminate/support[v11.0.0, ..., 11.x-dev]. They all replace spatie/once and thus cannot coexist.