how do i fix this error: RenderBox was not laid out: RenderRepaintBoundary#16fcb relayoutBoundary=up4 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE

Question

I have an error that says: RenderBox was not laid out: RenderDecoratedBox#dbfd0 relayoutBoundary=up12 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE. 'package:flutter/src/rendering/box.dart': Failed assertion: line 2001 pos 12: 'hasSize'

How can i fix this error. I have looked at the other questions and didn't came to an solution.

      body: SafeArea(
        child: SingleChildScrollView(
        physics: const BouncingScrollPhysics(),



      child: Container(
        decoration: BoxDecoration(
            gradient: LinearGradient(colors: [
              hexStringToColor("FFBEC8"),
              hexStringToColor("fe98a8"),
              hexStringToColor("FC98A7"),
              hexStringToColor("#FF8799")
            ], begin: Alignment.topCenter, end: Alignment.bottomCenter)),
          child: Padding(
              padding: EdgeInsets.all(16.0),

              child: Column(
                children: <Widget>[
                  Container(

                    height: 64,
                    margin: EdgeInsets.only(bottom: 20),
                    child: Row(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: <Widget>[
                        CircleAvatar(
                          radius: 29,
                          backgroundImage: AssetImage(
                              'assets/logo.png'),
                        ),
                        SizedBox(
                          width: 16,
                        ),
                        Column(
                          mainAxisAlignment: MainAxisAlignment.center,
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: <Widget>[
                            Text(

                        "$name",
                              style: TextStyle(
                                  fontFamily: "Montserrat Medium",
                                  color: Colors.white,
                                  fontSize: 20),
                            ),

                          ],
                        )
                      ],
                    ),

                  ),

                  Expanded(
                    child: GridView.count(
                      shrinkWrap: true,
                      mainAxisSpacing: 10,
                      crossAxisSpacing: 10,
                      primary: false,
                      crossAxisCount: 2,

                      children: <Widget>[
                        Card(
                          color: Colors.grey.shade100,
                          shape:RoundedRectangleBorder(
                              borderRadius: BorderRadius.circular(8)
                          ),

                          elevation: 4,
                          child: Column(
                            mainAxisAlignment: MainAxisAlignment.center,

                            children: <Widget>[
                              GestureDetector(
                                onTap:
                          () =>
                              Navigator.of(context).push(PageTransition(
                                  child: PDFScreen(pathPDF: 'assets/arbo',),
                                  type: PageTransitionType.fade)),


                                  child:
                                  SvgPicture.asset(
                                    'assets/moon.svg',
                                    height: 120,
                                  )

                              ),
                              Text(
                                'Arbo-lijst',

                                style: cardTextStyle,
                              )
                            ],
                          ),
                        ),

Answer 1

In my case the anwser was to remove the expended widged.