How to fix flutter app not launching with fatal exception after upgrading

Question

I recently upgraded flutter to 1.2 and on testing it on a real device it ends up crashing. Here's is the error it throws on the debug console:

E/AndroidRuntime(21890): FATAL EXCEPTION: main
E/AndroidRuntime(21890): Process: com.example.instagram_clone, PID: 21890
E/AndroidRuntime(21890): java.lang.RuntimeException: Unable to instantiate application io.flutter.app.FlutterApplication: java.lang.ClassNotFoundException: Didn't find class "io.flutter.app.FlutterApplication" on path: DexPathList[[zip file "/data/app/com.example.instagram_clone-Z7ozUBGogMCjxOJ-rLwCOQ==/base.apk"],nativeLibraryDirectories=[/data/app/com.example.instagram_clone-Z7ozUBGogMCjxOJ-rLwCOQ==/lib/arm, /system/lib, /vendor/lib]]
E/AndroidRuntime(21890):    at android.app.LoadedApk.makeApplication(LoadedApk.java:999)
E/AndroidRuntime(21890):    at android.app.ActivityThread.handleBindApplication(ActivityThread.java:5742)
E/AndroidRuntime(21890):    at android.app.ActivityThread.-wrap1(Unknown Source:0)
E/AndroidRuntime(21890):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1680)
E/AndroidRuntime(21890):    at android.os.Handler.dispatchMessage(Handler.java:106)
E/AndroidRuntime(21890):    at android.os.Looper.loop(Looper.java:164)
E/AndroidRuntime(21890):    at android.app.ActivityThread.main(ActivityThread.java:6523)
E/AndroidRuntime(21890):    at java.lang.reflect.Method.invoke(Native Method)
E/AndroidRuntime(21890):    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
E/AndroidRuntime(21890):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:857)
E/AndroidRuntime(21890): Caused by: java.lang.ClassNotFoundException: Didn't find class "io.flutter.app.FlutterApplication" on path: DexPathList[[zip file "/data/app/com.example.instagram_clone-Z7ozUBGogMCjxOJ-rLwCOQ==/base.apk"],nativeLibraryDirectories=[/data/app/com.example.instagram_clone-Z7ozUBGogMCjxOJ-rLwCOQ==/lib/arm, /system/lib, /vendor/lib]]
E/AndroidRuntime(21890):    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:125)
E/AndroidRuntime(21890):    at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
E/AndroidRuntime(21890):    at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
E/AndroidRuntime(21890):    at android.app.Instrumentation.newApplication(Instrumentation.java:1087)
E/AndroidRuntime(21890):    at android.app.LoadedApk.makeApplication(LoadedApk.java:993)
E/AndroidRuntime(21890):    ... 9 more

Any help will be appreciated. I also ran flutter upgrade , flutter pub get and flutter clean. I am testing the app on a real device and it worked before i upgraded.

Can you confirm if you have MainActivity.java or MainActivity.kt with the proper class declaration? — Sanjay Sharma
– Sanjay Sharma, Commented Aug 9, 2020 at 16:36
just make sure the package name on mainactivity.java or mainactivity.kt is correct — Basudev Nayak
– Basudev Nayak, Commented Apr 1, 2021 at 9:11

Devendra Shekhawat · Accepted Answer · 2021-11-12 06:47:46Z

3

Same issue. The reason I found is that I changed the package name in the AndroidManifest.xml files at Main, debug and profile in Android --> App.

Solved the issue by changing the Package name with the new one in MainActivity.Kt

answered Nov 12, 2021 at 6:47

Devendra Shekhawat

312 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

william · Accepted Answer · 2021-05-30 22:04:00Z

1

I changed com.example.myapp to match what I had used to set up firebase under myapp --> android --> app --> main --> kotlin --> myapp --> MainActivity.kt

answered May 30, 2021 at 22:04

william

111 bronze badge

1 Comment

Hanaa Over a year ago

did you changed the folder names ?

oryan · Accepted Answer · 2020-08-12 14:05:28Z

0

I managed to solve the problem by starting another project and copying lib file,pubspec.yaml and/or assets folder to the new project. Unfotunately i had to reconnect to firebase/or any other backend all over again.

answered Aug 12, 2020 at 14:05

oryan

11 silver badge4 bronze badges

Comments

Saabir Mohamed · Accepted Answer · 2023-03-20 14:16:38Z

-1

me too thats the only way , I started brand new project. copied Everything again ...had to do allot of changes. (3 times ) all backend again , all manifest build.gradle, podfile, info.plist and ALL that again however the easiest way a little faster... of your bundle is : com.domain.coolapp flutter create coolapp --org com.domain it some other location where the coolapp folder can be created without conflict...for me this happens when the location services (geolocator , location and such ). get funny and just crashes the app like crazy. also had to do this >adb shell , pm uninstall com.domain.coolapp, exit

answered Mar 20, 2023 at 14:16

Saabir Mohamed

746 bronze badges

Collectives™ on Stack Overflow

How to fix flutter app not launching with fatal exception after upgrading

4 Answers 4

Comments

1 Comment

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

1 Comment

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related