I erased in my folder .pub-cache/hosted/pub.dartlang.org/this_plugin
.pub-cache/hosted/pub.dartlang.org/this_plugin
What is the command to update the dependencies inside pubsec.yaml
pubsec.yaml
Remove the package from dependencies in pubspec.yaml, run flutter packages get. And then add the package to dependencies again and running flutter packages get.This process has solved the problem for me in the past.
dependencies
pubspec.yaml
flutter packages get