Overview:

In this guide I'll cover how to Fix the Black Screen issue in your Flutter. Sometime when we run our Flutter Application than Application stuck on the Black Screen and show nothing than after sometime he shows Application is not responding. This is a very famous error in Flutter Applications. Basically I'll guide you completely about this why this error occur and what precautions will save us from this error.


What is the black screen error in the Flutter Apps?

Basically Black Screen error in Flutter App is a very Common error and this error occur due to some different reasons. This is a very frustrating error for Developers. And some time developers stuck on this error so, I'm going to share some major reasons of this error. This error mostly happens due to these things.

  1. Missing Material Widget
  2. Syntax error in your Application
  3. Device is not supported
  4. Memory Issues
  5. Cache Problem
  6. Main thread is doing too much work
  7. Outdated Dependencies
  8. Problem with Flutter or Dart SDK(Outdated Version).
So I'll discuss these all things with you and than I will guide you how to fix this.

Missing Material Widget Cause Black Screen Error in Flutter:

Before Using Scaffold widget we Use material widget in our Flutter because Material widget is responsible for theme. So it's necessary to use Material Widget in the root of your Application otherwise your Application will show nothing or show Black Screen on start. This is a very common reason mostly beginner developers face this Problem when he start learning Flutter App Development.



Syntax Error Cause Black Screen in Your Flutter Application:

If you are using some methods in your Application Those who are performing some specific tasks. Like your Application has method which is checking internet permission when your Application starts. So if you made some mistakes in this method than you'll face this type of Black Screen errors. 



Device is not Supported:

We have SDK settings in Flutter Applications. So if your Emulator or Real Device SDK level is not matched with your Application SDK level than you face this Error only in debugging mode. But when you check this with Release version so while installing APK Android will inform you that this Application is not supported by your device.



Memory Issues:

If you are testing your Android Application on Emulator. Than may be due to this issue you are facing black screen issue in Flutter App. Sometime Background Apps in Windows takes extra RAM. So when you Run Emulator than Emulator shows lag because Emulator is not getting required Ram from your PC. And When you test your Application on this Emulator than Emulator shows more lag and kill all processes so that's why your Flutter Android Application shows Black Screen. 

Cache Problem:

While Debugging our Android Application makes some caches Like if you are Using Firebase Authentication than Android App keep the Login User Data in caches. So due to some caches Application Shows Black screen error. Force Stop the App Clear App Storage or Uninstall the Application than Re Install your Application. I hope so this method will help you to solve Black Screen Error in Flutter Application.

 Main Thread is Doing too much work:

We know in Flutter When we run our Application than first of all Application call the Main Method. If you are performing some heavy functions on your main thread For Example you are checking Internet Permission, Than you are checking is user is login or not, And at the same time you are initializing some SDK's. So you are performing too much functions on your Main thread so it's not a good Practice. In this way you are making your Application more slower and also your Application will consume more Ram at the same time. So some time due to Main Thread overload cause Black Screen Error in Flutter Applications.

Outdated Dependencies:

If you are using Firebase, or Any other Dependency in your Application than make sure you are using the latest version of dependencies, And also check is the current version of Dependency is compatible with your Flutter version or Not. Because if you are initializing the Outdated Dependencies on start of the App than you face these type black screen errors in Flutter.

Problem With SDK Version:

Always use the latest version of Flutter or Dark SDK. Many developers doesn't update the Flutter SDK that's why they face Black screen error. Type this Command in Terminal to Update Flutter SDK. It will take some time Depends on your Internet connection speed. Once Upgrading is finished than restart the IDE.
In order to Update Flutter SDK open Terminal and type flutter upgrade. 



Troubleshooting Tips to Fix Black screen error in Flutter Application:

If all above steps are not useful for you than try this method:

1: Clean your Project. To do this type Flutter clean in terminal it will take some time and Flutter will clean your Project. After that go to Pub Spec file and click on Pub get to fix all errors.
2: Update your IDE and Flutter SDK's.
3: Reboot your System than try it again.
4: Run Flutter Doctor command in CMD and check is Flutter Doctor is giving error's or not.

I hope these all steps are useful for you. But if your problem is not fixed and you are facing same error again and again. Than Click on build and generate Release APK and than check this APK on you real device. And if problem is same it's mean you are doing something wrong in your Code. So read your code carefully and find the bug. But if release APK is working fine on your Android but showing Black error only on Emulator and Follow these steps.

Go to Device Manager and select the emulator that you are using click on side three dots and you see multiple options click on Wipe data and than check I hope in this way you will solved your problem. But if error is same delete the Emulator and create new emulator and give some extra RAM to Hyper-V and Emulator. Than Check your Application.

Android Studio Software image while creating New Device