Gray Screen Issues in Flutter

Flutter is one of the best Application development tool right now. It has every things that an Application developer need. Moreover it is cross platform i.e. you can create application for Android, IOS, Windows, Mac, Linux, etc from a single code base.

But sometimes we may come upon a situation where the best also fails to give result as expected. In Flutter, Many of the starters face the “Gray Screen” issue. This issue can cause a headache to developer because the fully functional Flutter app in debug mode starts to show gray screen in release mode. But as for every problem there is a solution and this “Gray Screen” issue is not an exception to that.

So How do we prevent ourself from these Gray Screen issues?

We as a developer usually ignore warnings and rather focus just on the red screen errors in flutter. If that’s the case in you too, then you will surely get a Gray Screen issue in your release app. So focus on each and every error in console even if your app is working nicely. The error casuing “gray screen” usually looks like this:

════════ Exception caught by widgets library ═══════════════════════════════════════════════════════ The following assertion was thrown while applying parent data.: Incorrect use of ParentDataWidget. The ParentDataWidget Expanded(flex: 1) wants to apply ParentData of type FlexParentData to a RenderObject, which has been set up to accept ParentData of incompatible type StackParentData. Usually, this means that the Expanded widget has the wrong ancestor RenderObjectWidget. Typically, Expanded widgets are placed directly inside Flex widgets. The offending Expanded is currently placed inside a Stack widget.

Final Conclusion

To prevent yourself from Gray screen errors, See the errors while running debug app. These errors look like the one showed up. Correct that UI part which are causing errors. Never ignore any errors on the console. Stop just focusing on the red screen errors. And you will never ever get Gray screen errors ever again.


I am a Software developer usually focusing on mobile development using Android SDK, Flutter, React Native and Swift.