Error: Member not found: ‘packageRoot’, how to solve ignore: deprecated_member_use in Flutter?

You need to upgrade your dependencies to fix this issue, so run:

flutter pub upgrade

If this still doesn’t work then it means you are having this issue from transitive dependencies on platform (platform with version lower than 3.1.0 has this problem). So, override the platform package in your pubspec.yaml file like this:

dependency_overrides:
  platform: ^3.1.0