Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires drush/drush ^9 -> satisfiable by drush/drush[9.0.0, ..., 9.7.3]. - drush/drush[9.0.0, ..., 9.4.0] require symfony/process ~2.7|^3 -> found symfony/process[v2.7.0, ..., v2.8.52, v3.0.0, ..., v3.4.47] but these were not loaded, because they are affected by security advisories. To ignore the advisories, add ("PKSA-wws7-mr54-jsny") to the audit "ignore" config. To turn the feature off entirely, you can set "block-insecure" to false in your "audit" config. - drush/drush[9.5.0, ..., 9.7.3] require symfony/process ^3.4 -> found symfony/process[v3.4.0, ..., v3.4.47] but these were not loaded, because they are affected by security advisories. To ignore the advisories, add ("PKSA-wws7-mr54-jsny") to the audit "ignore" config. To turn the feature off entirely, you can set "block-insecure" to false in your "audit" config.