Flutter: "RenderFlex children have non-zero flex but incoming height constraints are unbounded"

Wrap your Column inside an Expanded or SizedBox (with some height) like this:

Expanded(
  child: Column(...)
)

OR

SizedBox(
  height: 200, // Some height
  child: Column(...),
)

Try to wrap of Column or any of other Widget in Expanded or Flexible and it Will be done.

And Don't forget to give some height to the Scrolling widgets

The fix for this above issue, is to Wrap the Column widget inside a Expanded widget. Example below.

 Expanded(
   child: Column(
     children: <Widget>[
        Container(
           height: 400,
           width: 400,
           child: ListView.builder(
              itemCount: 2,
              itemBuilder: (context, position) {
                return Card(
                   child: Padding(
                     padding: const EdgeInsets.all(16.0),
                     child: Text("e.g., those that are not Expanded"),
                     ),
                  );
                },
             ),
          ),
       ],
    ),
 )

To understand more see this : “RenderFlex children have non-zero flex…”

This approach never fails me:

Card(
    child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
                Text("Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus finibus luctus tortor id pulvinar. Donec sollicitudin, dui vitae aliquam tristique, eros risus commodo enim, eget lobortis arcu velit ac arcu. "),
                Text("Nunc tristique, ex ut volutpat feugiat, nulla nibh iaculis lectus, laoreet auctor justo tellus quis mi. Praesent ut interdum sem. Donec eget finibus augue, et vehicula elit. Praesent eu euismod arcu, eu maximus tellus. Ut diam est, sodales nec enim a, pharetra lobortis erat."),
            ]
     )
)