Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires neos/seo dev-build as 4.x-dev, found neos/seo[dev-task/adjust-hiddenInIndex-to-core-changes, dev-feature/addPhpstan, dev-master, dev-ee64811fba9740b833e96f290285f5e184edb44f, dev-dlubitz-patch-1, dev-bugfix/language-fallback-handling, 1.0.0, ..., 1.0.x-dev, 2.0.0, ..., 2.1.x-dev, 3.0.0, ..., 3.x-dev, 4.0.0, ..., 4.x-dev] but it does not match the constraint. Problem 2 - Root composer.json requires neos/demo 9.0.x-dev -> satisfiable by neos/demo[9.0.x-dev]. - neos/demo 9.0.x-dev requires neos/seo ~4.1 -> found neos/seo[4.1.0, ..., 4.x-dev] but it conflicts with your root composer.json require (dev-build as 4.x-dev).

Process completed with exit code 2.