FadeInImage.assetNetworkで存在するのにエラー？

Null check operator used on a null value

なるエラーがFadeInImage.assetNetworkで発生

  @override
  Widget build(BuildContext context) {
    final copiedUrl = imageUrl;

    if (copiedUrl == null || copiedUrl.isEmpty) {

    } else {
      print('おかしいかい？');
      print(copiedUrl);
      imageWidget = FadeInImage.assetNetwork(
        image: copiedUrl,
        placeholder: 'images/icon_loading@2x.png',

ログ見ても存在している・・・

flutter: おかしいかい？
flutter: https://存在してる.png

======== Exception caught by widgets library =======================================================
The following _CastError was thrown building _AnimatedFadeOutFadeIn(duration: 1000ms, dirty, state: _AnimatedFadeOutFadeInState#a07bb(ticker inactive, targetOpacity: null, placeholderOpacity: null)):
Null check operator used on a null value

AndroidStudioの問題？ https://halzoblog.com/error-bug-diary/20221009-2/