Why getting this error Cannot resolve symbol 'menu' in onCreateOptionsMenu?

In R.menu I am getting this error.
@override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_apk_list, menu);
return true;
}

from Android Forums at AndroidCentral.com - Ask a Question http://ift.tt/2xu8HIL
via IFTTT