Android Studio "cannot Resolve Symbol Xxx" On Basic Android Tutorial

I'm doing the entry level tutorial on the official Android docs. I'm currently at this step where I'm creating the second activity: http://developer.android.com/training/basics/fir

Solution 1:

I just did an update to 0.26 and had the same problem. CLosing the project, and restarting Android studio and then opening the project seems to have cleared whatever it was that was causing this.

Solution 2:

so, it turns out that Studio is (understandibly) buggy, and that these errors are false negatives...

I can also add the hierarchical parent by hand in the code so the question about the popup is moot too :/