Official errata thread for Flutter Apprentice, First Edition!
Errata for First Edition - Early Access 2; Dart 2.9, Flutter 1.20, AS 4.0.1
In Chapter 3 “Basic Widgets”, exactly at the “Using the themes” section below the After all your updates, replace all headline6 with headline3, since the FooderlichTheme class definition only determines the styles up to headline3.
I used VSCode 1.52.1 at the time of writing this – I noticed a weird thing: the themes didn’t apply right away the first time, even hot reloads or hot restarts didn’t fix them. Probably it’s a limitation in the extension. If it does occur, just stop the debugger and run again, not do a hot restart, and it should go well.
@skibaro thanks 
We took a note and we’ll address this in the next release.
Of particular import to general app development is the make up of the framework layer.
import → important
OK. Got it. That’s a rare use case for import!
descending widgets → descendant widgets in Chapter 6.
Thanks.
This is fixed in the upcoming release.