Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires php-cs-fixer/shim 3.19.1 -> satisfiable by php-cs-fixer/shim[v3.19.1]. - Root composer.json requires tenantcloud/php-cs-fixer-rule-sets ~3.3.1 -> satisfiable by tenantcloud/php-cs-fixer-rule-sets[v3.3.1]. - tenantcloud/php-cs-fixer-rule-sets v3.3.1 requires friendsofphp/php-cs-fixer ^3.54 -> satisfiable by friendsofphp/php-cs-fixer[v3.54.0, ..., v3.65.0]. - Only one of these can be installed: friendsofphp/php-cs-fixer[v3.50.0, ..., v3.65.0], php-cs-fixer/shim[v3.19.1]. php-cs-fixer/shim replaces friendsofphp/php-cs-fixer and thus cannot coexist with it.