NotWidgetException in example

[Jonbeckas]

I have this issue: when I try to run the example on Flutter 2.5.2.

Does somebody know what this means?

════════ Exception caught by widgets library ═══════════════════════════════════
The following NotWidgetException was thrown building XmlLayout(dirty, state: XmlLayoutState#e2833):
Instance of 'NotWidgetException'

The relevant error-causing widget was
XmlLayout
lib\main.dart:119
When the exception was thrown, this was the stack
C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/internal/js_dev_runtime/private/ddc_runtime/errors.dart 251:49 throw
packages/xml_layout/xml_layout.dart 256:7 build
packages/flutter/src/widgets/framework.dart 4782:27 build
packages/flutter/src/widgets/framework.dart 4665:15 performRebuild

[wahabsohail]

I'm facing the same issue in flutter 2.10.4.

════════ Exception caught by widgets library═══════════════════════════════════
The following NotWidgetException was thrown building XmlLayout(dirty, state: XmlLayoutState#36856):
Instance of 'NotWidgetException'

The relevant error-causing widget was
XmlLayout
lib\main.dart:113
When the exception was thrown, this was the stack