I started working with recyclerview and cardview and then I had to put a dependency and when it was synchronized the build sent me this error, I already deleted the activitys and classes that I used, I also deleted the dependencies that I did not need and I updated the android studio and It did not work:
url is not registered http //schemas.android.com/apk/res/android
manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.luisfrancisco.sinfilarregional