Failed to find assets path for "Frameworks/App.framework/flutter_assets"

Question

I'm trying to run my flutter app on the simulator ( iPhone 8 ) but when the app lunches all I get is a blank white screen. like this:

Terminal output is:

Running pod install...                                             40.0s
Running Xcode build...                                                  

 ├─Assembling Flutter resources...                          20.4s
 └─Compiling, linking and signing...                        57.0s
Xcode build done.                                           288.8s
        path: satisfied (Path is satisfied), interface: en1
Failed to find assets path for "Frameworks/App.framework/flutter_assets"
Configuring the default Firebase app...
        path: satisfied (Path is satisfied), interface: en1
        path: satisfied (Path is satisfied), interface: en1
Configured the default Firebase app __FIRAPP_DEFAULT.
[VERBOSE-2:engine.cc(127)] Engine run configuration was invalid.
[VERBOSE-2:shell.cc(437)] Could not launch engine with configuration.
https://firebase.google.com/docs/cloud-messaging/ios/client#method_swizzling_in_firebase_messaging
to ensure proper integration.                                           
Syncing files to device iPhone 8...                                     
10,195ms (!)

I'm using the stable version of flutter 1.12.13+hotfix.9, and this issue appears only on ios building.

How can I solve this issue?

Answer 1

I've just managed to solve this issue. I've just followed advise https://github.com/flutter/flutter/issues/29974 and added "$FLUTTER_ROOT/packages/flutter_tools/bin/xcode_backend.sh" embed to Run script Run script After rebuilding App.framework folder has been added to build directory and problem has gone. Hope this will help someone else.

Answer 2

You can follow the instructions in https://flutter.dev/docs/development/ios-project-migration

Particularly the build phase:

/bin/sh "$FLUTTER_ROOT/packages/flutter_tools/bin/xcode_backend.sh" embed
/bin/sh "$FLUTTER_ROOT/packages/flutter_tools/bin/xcode_backend.sh" thin

You can see more here: https://github.com/flutter/flutter/issues/52084#issuecomment-600768772