Your requirements could not be resolved to an installable set of packages. Problem 1 - ibexa/user dev-main requires ibexa/notifications ~5.0.0@dev -> found ibexa/notifications[dev-main, 5.0.x-dev (alias of dev-main)] but it does not match your minimum-stability. - ibexa/user 5.0.x-dev is an alias of ibexa/user dev-main and thus requires it to be installed too. - Root composer.json requires ibexa/user ~5.0.x-dev -> satisfiable by ibexa/user[5.0.x-dev (alias of dev-main)].