i get error when try run app

[AnasProgrammer2]

/C:/src/flutter/.pub-cache/hosted/pub.dartlang.org/getflutter-1.1.3/lib/components/appbar/gf_appbar.dart:311:57: Error: No named parameter with the name 'nullOk'.
final ScaffoldState scaffold = Scaffold.of(context, nullOk: true);
^^^^^^
/C:/src/flutter/packages/flutter/lib/src/material/scaffold.dart:1944:24: Context: Found this candidate, but the arguments don't match.
static ScaffoldState of(BuildContext context) {
^^
3

FAILURE: Build failed with an exception.

• Where:
  Script 'C:\src\flutter\packages\flutter_tools\gradle\flutter.gradle' line: 991

[0wzZZzz6]

try changing the getflutter in pubspec into getwidget