Xcode 11 Beta 3, build error “Unknown attribute 'State'”, “Use of undeclared type 'View'” etc

Question

I build an app with the 2nd beta of Xcode 11, using SwiftUI, and everything worked completely fine, but now, with the 3rd beta, the app isn\'t even build. I get errors like

Answer 1

I was getting the same "Unknown attribute 'State'" issue in Beta 5. But I was doing "@state" and not "@State". Case matters. It's hard to notice because both ways are shown as purple.