Cannot resolve symbol AppCompatActivity - Support v7 libraries aren't recognized?

Question

I\'m trying to figure out why the heck my Android studio isn\'t recognizing the AppCompat v7 library correctly. The import statement below shows up as gray and says there\'s

Answer 1

After invalidating Cache, changing from

import android.support.v7.app.AppCompatActivity;

to

import androidx.appcompat.app.AppCompatActivity;

worked for me.