Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires maglnet/composer-require-checker 2.0 -> satisfiable by maglnet/composer-require-checker[2.0.0]. - Root composer.json requires symfony/http-kernel ^4.4|^5.0 -> satisfiable by symfony/http-kernel[v5.3.0, ..., v5.3.16]. - maglnet/composer-require-checker 2.0.0 requires symfony/console ^3.4.17 | ^4.1.6 -> satisfiable by symfony/console[v4.4.0, ..., v4.4.49]. - symfony/console[v4.4.27, ..., v4.4.49] conflict with symfony/event-dispatcher v5.4.0. - symfony/console[v4.4.27, ..., v4.4.49] conflict with symfony/event-dispatcher v5.2.12. - symfony/console[v4.4.27, ..., v4.4.49] conflict with symfony/event-dispatcher v5.1.0. - symfony/console[v4.4.27, ..., v4.4.49] conflict with symfony/event-dispatcher v5.0.9. - symfony/console[v4.4.27, ..., v4.4.49] conflict with symfony/event-dispatcher v5.0.0. - symfony/http-kernel[v5.3.0, ..., v5.3.16] require symfony/event-dispatcher ^5.0 -> satisfiable by symfony/event-dispatcher[v5.0.0, ..., v5.4.45]. - Conclusion: don't install symfony/console v4.4.0 (conflict analysis result) - Conclusion: don't install symfony/console v4.4.9 (conflict analysis result) - Conclusion: don't install symfony/console v4.4.21 (conflict analysis result) Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.