With a team of skilled Flutter developers, you can easily identify common run-time issues such as state management issues, missing assets, and more. Effectively debugging these issues requires a combination of tools, a solid understanding of the framework, and pattern-based thinking. Below are key issues and their solutions.

1. “setState() or markNeedsBuild() called during build.”

Cause: You’re calling setState() inside the build() method or during widget construction.

Fix:

Dart:

@override
void initState() { super.initState(); Future.delayed(Duration.zero, () { setState(() { // safe to modify state here }); });
}

2. “RenderFlex overflowed” (red-yellow warning bar)

Cause: A widget is trying to render beyond the available screen space, especially in Row or Column.

Fix:

Use Flexible, Expanded, or wrap with SingleChildScrollView.

Dart:

SingleChildScrollView( child: Column( children: [...], ),
);

3.  “setState() called after dispose()”

Cause: An async call is still executing after the widget gets removed from the widget tree.

Fix:

Check `mounted` before calling `setState()`:

Dart:

if (mounted) { setState(() => isLoading = false);
}

Pro Tips

  • Always wrap long async logic in try/catch and guard with mounted
  • Use Flutter DevTools for inspecting UI and memory.
  • Use FlutterError.onError for global error capture in production