Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires wp-cli/i18n-command dev-main -> satisfiable by wp-cli/i18n-command[dev-main]. - wp-cli/i18n-command dev-main requires wp-cli/wp-cli ^2.12 -> found wp-cli/wp-cli[2.11.0] but it does not match the constraint. See https://getcomposer.org/dep-on-root for details and assistance.