Your requirements could not be resolved to an installable set of packages. Problem 1 - localgovdrupal/localgov is locked to version 3.x-dev and an update of this package was not requested. - localgovdrupal/localgov 3.x-dev requires localgovdrupal/localgov_alert_banner ^1.2.0 -> found localgovdrupal/localgov_alert_banner[1.2.0, ..., 1.x-dev] but it conflicts with your root composer.json require (dev-fix/345-add-banner-type-accessible-name as 1).