No resource identifier found for attribute '...' in package 'com.app....'

I was facing the same problem and solved it using the below steps:

Add this in your app's build.gradle

android {
    defaultConfig {
        vectorDrawables.useSupportLibrary = true
    }
}

Use namespace:

xmlns:app="http://schemas.android.com/apk/res-auto"

Then use:

app:srcCompat="@drawable/your_vector_drawable_here"

I just changed:

xmlns:app="http://schemas.android.com/apk/res-auto" 

to:

xmlns:app="http://schemas.android.com/apk/lib/com.app.chasebank"

and it stopped generating the errors, com.app.chasebank is the name of the package. It should work according to this Stack Overflow : No resource identifier found for attribute 'adSize' in package 'com.google.example' main.xml

You can also use lib-auto

 xmlns:app="http://schemas.android.com/apk/lib-auto"