The following _TypeError was thrown building PrimaryScrollController(_NestedScrollController#82ad6(inner, no clients)):

The following _TypeError was thrown building PrimaryScrollController(_NestedScrollController#82ad6(inner, no clients)):

Null check operator used on a null value

 class PostDataListMenu extends StatefulWidget {

  final PostData? postdata;

  PostDataListMenu({Key? key, this.postdata}) : super(key: key);

  @override
  _PostDataListMenu createState() => _PostDataListMenu(postdata!);
}

수정 후  -- null check  수정

class _PostDataListNotice extends State<PostDataListNotice> {
  final PostData? postdata;
  final ScrollController _scrollController = ScrollController();

  _PostDataListNotice(this.postdata);

  @override
  void initState() {
    super.initState();
  }

_PostDataListMenu createState() => _PostDataListMenu(postdata);