Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires nails/module-invoice dev-feature/pre-new-admin -> satisfiable by nails/module-invoice[dev-feature/pre-new-admin]. - nails/module-invoice dev-feature/pre-new-admin requires nails/skin-invoice-classic dev-feature/pre-new-admin -> satisfiable by nails/skin-invoice-classic[dev-feature/pre-new-admin] from composer repo (https://repo.packagist.org) but nails/skin-invoice-classic dev-develop is the root package and cannot be modified. See https://getcomposer.org/dep-on-root for details and assistance.

Process completed with exit code 2.