Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires phpcr/phpcr-implementation ^2.1, it could not be found in any version, but the following packages provide it: - jackalope/jackalope Jackalope PHPCR library - 7rin0/seven-manager Seven Manager - midgard/phpcr PHP Content Repository implementation using Midgard2 Consider requiring one of these to satisfy the phpcr/phpcr-implementation requirement. Problem 2 - Root composer.json requires jackalope/jackalope-doctrine-dbal 2.0@dev (exact version match), found jackalope/jackalope-doctrine-dbal[dev-cache_queries_node_types, dev-node_was_deleted, dev-join-on-issamenode, dev-versioning, dev-symfony-7, dev-allow_overwriting_uuid, 1.0.0-alpha1, ..., 1.x-dev, 2.0.0-beta1, 2.0.0-beta2, 2.x-dev] but it does not match the constraint. Potential causes: - A typo in the package name - The package is not available in a stable-enough version according to your minimum-stability setting see <https://getcomposer.org/doc/04-schema.md#minimum-stability> for more details. - It's a private package and you forgot to add a custom repository to find it Read <https://getcomposer.org/doc/articles/troubleshooting.md> for further common problems.