Android X: tools:replace specified at line: for attribute, but no new value specified
I think you are migrating to AndroidX libs. Add below lines to gradle.properties file android.useAndroidX=true android.enableJetifier=true Remove tools:replace=”android:appComponentFactory” from manifest. Replace import from android.support.v7.app.AppCompatActivity to androidx.appcompat.app.AppCompatActivity in activities. Use replace in project to expedite the process of refactoring. Migrating to AndroidX