Your requirements could not be resolved to an installable set of packages. Problem 1 - symfony/error-handler[v4.4.0, ..., v4.4.44, v5.0.0, ..., v5.3.14] require symfony/var-dumper ^4.4|^5.0 -> found symfony/var-dumper[v4.4.0, ..., v4.4.47, v5.0.0, ..., v5.4.35] but it conflicts with your root composer.json require (^3.4). - symfony/error-handler[v5.4.0, ..., v5.4.35] require symfony/var-dumper ^4.4|^5.0|^6.0 -> found symfony/var-dumper[v4.4.0, ..., v4.4.47, v5.0.0, ..., v5.4.35, v6.0.0, ..., v6.4.3] but it conflicts with your root composer.json require (^3.4). - symfony/framework-bundle v4.4.0 conflicts with symfony/browser-kit v3.4.47. - symfony/framework-bundle[v4.4.1, ..., v4.4.51] require symfony/error-handler ^4.4.1|^5.0.1 -> satisfiable by symfony/error-handler[v4.4.1, ..., v4.4.44, v5.0.1, ..., v5.4.35]. - Root composer.json requires symfony/browser-kit ^3.4 -> satisfiable by symfony/browser-kit[v3.4.0, ..., v3.4.47]. - Root composer.json requires symfony/framework-bundle ^4.4 -> satisfiable by symfony/framework-bundle[v4.4.0, ..., v4.4.51].