Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires yiisoft/yii2 2.2.x-dev -> satisfiable by yiisoft/yii2[2.2.x-dev]. - yiisoft/yii2 2.2.x-dev requires bower-asset/inputmask ^5.0.8 -> found bower-asset/inputmask[5.0.8-beta.0, ..., 5.x-dev] but the package is fixed to 3.3.11 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command. Problem 2 - yiisoft/yii2 2.2.x-dev requires bower-asset/inputmask ^5.0.8 -> found bower-asset/inputmask[5.0.8-beta.0, ..., 5.x-dev] but the package is fixed to 3.3.11 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command. - yii2-extensions/phpstan 0.1.0 requires yiisoft/yii2 ^2.0.49 || ^2.2 -> satisfiable by yiisoft/yii2[2.2.x-dev]. - yii2-extensions/phpstan is locked to version 0.1.0 and an update of this package was not requested. Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.