Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires larastan/larastan ^2.9 -> satisfiable by larastan/larastan[v2.9.0, ..., v2.9.14]. - Root composer.json requires orchestra/testbench ^10 -> satisfiable by orchestra/testbench[v10.0.0, v10.1.0]. - larastan/larastan[v2.9.9, ..., v2.9.14] require illuminate/contracts ^9.52.16 || ^10.28.0 || ^11.16 -> satisfiable by illuminate/contracts[v10.28.0, ..., v10.48.28, v11.16.0, ..., v11.44.1]. - larastan/larastan[v2.9.0, ..., v2.9.8] require illuminate/contracts ^9.52.16 || ^10.28.0 || ^11.0 -> satisfiable by illuminate/contracts[v10.28.0, ..., v10.48.28, v11.0.0, ..., v11.44.1]. - Conclusion: don't install illuminate/contracts v10.48.28 (conflict analysis result) - Conclusion: don't install illuminate/contracts v11.44.1 (conflict analysis result) Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.