Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires yii2-extensions/debug dev-improve-config, found yii2-extensions/debug[dev-main, 1.0.x-dev (alias of dev-main)] but these do not match your constraint and are therefore not installable. Make sure you either fix the constraint or avoid updating this package to keep the one present in the lock file (yii2-extensions/debug[dev-improve-config]).