Mapping values are not allowed here. Did you miss a colon earlier?

Solution 1:

Spaces are important in YAML file. So Please remove space before -asset: instead of this

flutter:
  uses-material-design: true
   assets:
     - assets/images/

fix it like this way

flutter:
  uses-material-design: true
  assets:
     - assets/images/

Solution 2:

In my case I just should have to rename my "assets" folder to some another one. There was this error when I had such code

assets: - assets/image.jpg

I replaced to this:

assets: - images/image.jpg

Solution 3:

firebase_auth looks out of place. Also there are indentation issues. Can you try this below?

name: masque
version: 1.0.0+1
dependencies: 
  flutter:
    sdk: flutter
  firebase_auth: ^0.11.1+3
description: "A new Flutter application."
dev_dependencies: 
  flutter_test:
    sdk: flutter
flutter:
  uses-material-design: true