FlutterError (Cannot get renderObject of inactive element.
In order for an element to have a valid renderObject, it must be active, which means it is part of the tree.
Instead, this element is in the _ElementLifecycle.inactive state.
If you called this method from a State object, consider guarding it with State.mounted.
The findRenderObject() method was called for the following element:
  LayoutBuilder)

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:showcaseview/showcaseview.dart';
import 'package:get/get.dart';
import 'package:responsive_sizer/responsive_sizer.dart';

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();

  runApp(const TestApp());
}

class TestApp extends StatefulWidget {
  const TestApp({super.key});

  @override
  State<TestApp> createState() => _TestAppState();
}

class _TestAppState extends State<TestApp> {
  @override
  Widget build(BuildContext context) {
    return ResponsiveSizer(
      builder: (context, orientation, sizingInformation) => GetMaterialApp(
        initialRoute:
            '/', //No cambiar por /mapa, dado que el inicio desde dynamic link dara error
        defaultTransition: Transition.native,
        getPages: [
          GetPage(
              name: '/',
              participatesInRootNavigator: true,
              page: () => const View1()),
          GetPage(name: '/two', page: () => const View2()),
        ],
      ),
    );
  }
}

class View1 extends StatefulWidget {
  const View1({super.key});

  @override
  State<View1> createState() => _View1State();
}

class _View1State extends State<View1> {
  final keyOne = GlobalKey<ShowCaseWidgetState>();

  static bool firstTime = true;

  @override
  Widget build(BuildContext context) {
    return ShowCaseWidget(builder: Builder(builder: (cs) {
      if (firstTime) {
        firstTime = false;
        WidgetsBinding.instance.addPostFrameCallback((_) {
          ShowCaseWidget.of(cs).startShowCase([keyOne]);
        });
      }
      return Column(
        mainAxisAlignment: MainAxisAlignment.spaceAround,
        children: [
          Showcase(
              key: keyOne,
              description: 'One',
              child: ElevatedButton(
                child: const Text('ONE'),
                onPressed: () {
                  Get.offAllNamed('/two');
                },
              )),
        ],
      );
    }));
  }
}

class View2 extends StatefulWidget {
  const View2({super.key});

  @override
  State<View2> createState() => _View2State();
}

class _View2State extends State<View2> {

  @override
  Widget build(BuildContext context) {
    return Column(
      mainAxisAlignment: MainAxisAlignment.spaceAround,
      children: [
        ElevatedButton(
          child: const Text('TWO'),
          onPressed: () {
            Get.offAllNamed('/');
          },
        ),
      ],
    );
  }
}

name: testapp
description: "A new Flutter project."

publish_to: 'none' # Remove this line if you wish to publish to pub.dev

version: 1.0.0+1

environment:
  sdk: '>=3.4.1 <4.0.0'

dependencies:
  flutter:
    sdk: flutter

  cupertino_icons: ^1.0.6
  responsive_sizer: ^3.3.1
  get: ^4.6.6
  showcaseview: 
    path: ../forks/flutter_showcaseview

dev_dependencies:
  flutter_test:
    sdk: flutter

  flutter_lints: ^3.0.0


flutter:
  uses-material-design: true

[✓] Flutter (Channel stable, 3.22.1, on macOS 14.5 23F79 darwin-arm64, locale es-AR)
    • Flutter version 3.22.1 on channel stable at /Users/pablo/Proyectos/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision a14f74ff3a (9 days ago), 2024-05-22 11:08:21 -0500
    • Engine revision 55eae6864b
    • Dart version 3.4.1
    • DevTools version 2.34.3

[✓] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
    • Android SDK at /Users/pablo/Library/Android/sdk
    • Platform android-34, build-tools 34.0.0
    • ANDROID_HOME = /Users/pablo/Library/Android/sdk
    • ANDROID_SDK_ROOT = /Users/pablo/Library/Android/sdk
    • Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 17.0.10+0-17.0.10b1087.21-11572160)
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    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 15F31d
    • CocoaPods version 1.15.2

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2023.3)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 17.0.10+0-17.0.10b1087.21-11572160)

[✓] VS Code (version 1.89.1)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.91.20240529