🐛 [firebase_storage] An unknown error occurred while calling method Reference#getDownloadURL when using Storage Emulator

[rignaneseleo]

Bug report

After updating the firebase libraries (check below the old and new versions), I get this error on iOS (both physical and simulator):

FLTFirebaseStorage: An unknown error occurred while calling method Reference#getDownloadURL
2022-10-25 10:37:57.073419+0200 Runner[95060:20882028] flutter: error: Upload error: [firebase_storage/unknown] An unknown error occurred, please check the server response.
2022-10-25 10:37:57.075673+0200 Runner[95060:20882028] flutter: URL:null

I have updated my firebase libraries from

  firebase_core: 1.24.0
  firebase_auth: 3.11.2
  firebase_storage: 10.3.11
  firebase_messaging: 13.1.0
  cloud_firestore: 3.5.1

to

  firebase_core: 2.1.0
  firebase_auth: 4.0.2
  firebase_storage: 11.0.2
  firebase_messaging: 14.0.2
  cloud_firestore: 4.0.2

Steps to reproduce

Steps to reproduce the behavior:

1. Execute fileRef.putFile()
2. Check if the state of the upload is successful
3. Run fileRef.getDownloadURL()
4. See error

Expected behavior

The URL of the file should be returned like it did using the old firebase libraries.

Sample code

This is the code I'm using:

 Reference storageRef = FirebaseStorage.instance.ref();

  if (intoUserArea) {
    var user = await PhoneAuthService.getUser();
    if (user == null) return null;
    storageRef = storageRef
        .child("authusers")
        //.child(globals.shareId.toString())
        .child(user.uid)
        .child(cloudFolder);
  } else
    storageRef = storageRef
        .child("shared")
        .child(globals.shareId.toString())
        .child(cloudFolder);

 var fileRef = storageRef.child(customFilename);

  try {
    await fileRef.putFile(
      File(filePath),
      SettableMetadata(
          contentType: mime(customFilename.toLowerCase()),
          customMetadata: {
            "deviceUUID": await getUUID(),
            "version": globals.printVersion(),
            "datetimeSinceEpoch":
                DateTime.now().toUtc().millisecondsSinceEpoch.toString()
          }),
    );

    final String url = (await fileRef.getDownloadURL());
    print('File uploaded on FirebaseStorage: $url');
    return url;
  } catch (e) {
    lError("Upload error: $e"); // FirebaseException
    return null;
  }

---

Flutter doctor

Run flutter doctor and paste the output below:

Click To Expand

[✓] Flutter (Channel stable, 3.3.4, on macOS 12.6 21G115 darwin-arm, locale en-US)
[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
[✓] Xcode - develop for iOS and macOS (Xcode 14.0.1)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2021.3)
[✓] VS Code (version 1.72.2)
[✓] Connected device (3 available)
[✓] HTTP Host Availability

• No issues found!

---

Flutter dependencies

Run flutter pub deps -- --style=compact and paste the output below:

Click To Expand

Dart SDK 2.18.2
Flutter SDK 3.3.4
my_family 2.0.1+201

dependencies:
- after_layout 1.1.0 [flutter]
- animate_do 2.0.0 [flutter]
- auto_size_text 3.0.0 [flutter]
- cached_network_image 3.2.0 [flutter flutter_cache_manager octo_image cached_network_image_platform_interface cached_network_image_web]
- chewie 1.2.2 [cupertino_icons flutter provider video_player wakelock]
- cloud_firestore 4.0.2 [cloud_firestore_platform_interface cloud_firestore_web collection firebase_core firebase_core_platform_interface flutter meta]
- connectivity 3.0.6 [flutter meta connectivity_platform_interface connectivity_macos connectivity_for_web]
- contacts_service 0.6.3 [flutter collection quiver]
- device_info_plus 4.1.2 [flutter device_info_plus_platform_interface device_info_plus_macos device_info_plus_linux device_info_plus_web device_info_plus_windows]
- dio 4.0.4 [http_parser path]
- draggable_scrollbar 0.1.0 [flutter]
- encrypt 5.0.1 [args asn1lib clock collection crypto pointycastle]
- file_picker 5.0.1 [flutter flutter_web_plugins flutter_plugin_android_lifecycle plugin_platform_interface ffi path win32]
- firebase_auth 4.0.2 [firebase_auth_platform_interface firebase_auth_web firebase_core firebase_core_platform_interface flutter meta]
- firebase_core 2.1.0 [firebase_core_platform_interface firebase_core_web flutter meta]
- firebase_messaging 14.0.2 [firebase_core firebase_core_platform_interface firebase_messaging_platform_interface firebase_messaging_web flutter meta]
- firebase_storage 11.0.2 [firebase_core firebase_core_platform_interface firebase_storage_platform_interface firebase_storage_web flutter]
- flutter 0.0.0 [characters collection material_color_utilities meta vector_math sky_engine]
- flutter_colorpicker 1.0.3 [flutter]
- flutter_custom_tabs 1.0.4 [flutter flutter_custom_tabs_platform_interface flutter_custom_tabs_web meta]
- flutter_fab_dialer 0.1.1 [flutter]
- flutter_image_compress 1.1.0 [flutter]
- flutter_launcher_icons 0.9.2 [args image path yaml]
- flutter_localizations 0.0.0 [flutter intl characters clock collection material_color_utilities meta path vector_math]
- flutter_mailer 2.0.1 [flutter]
- flutter_secure_storage 5.0.2 [meta flutter flutter_secure_storage_linux flutter_secure_storage_macos flutter_secure_storage_platform_interface flutter_secure_storage_web flutter_secure_storage_windows]
- flutter_slidable 0.6.0 [flutter]
- flutter_staggered_grid_view 0.6.1 [flutter]
- flutter_typeahead 4.1.0 [flutter flutter_keyboard_visibility]
- fluttertoast 8.0.8 [flutter flutter_web_plugins]
- font_awesome_flutter 9.2.0 [flutter]
- gallery_saver 2.1.0 [flutter path_provider http path]
- get 4.6.1 [flutter]
- google_fonts 2.2.0 [flutter http path_provider crypto]
- google_sign_in 5.4.2 [flutter google_sign_in_android google_sign_in_ios google_sign_in_platform_interface google_sign_in_web]
- heic_to_jpg 0.1.3 [flutter]
- http 0.13.4 [async http_parser meta path]
- image_picker 0.8.4+5 [flutter flutter_plugin_android_lifecycle image_picker_for_web image_picker_platform_interface]
- json_annotation 4.4.0 [meta]
- media_gallery 0.1.3 [flutter]
- mime_type 1.0.0
- package_info 2.0.2 [flutter]
- page_indicator 0.4.1 [flutter]
- page_transition 2.0.5 [flutter]
- path_provider 2.0.11 [flutter path_provider_android path_provider_ios path_provider_linux path_provider_macos path_provider_platform_interface path_provider_windows]
- permission_handler 10.0.0 [flutter meta permission_handler_android permission_handler_apple permission_handler_windows permission_handler_platform_interface]
- photo_manager 2.4.0 [flutter]
- photo_view 0.13.0 [flutter]
- printing 5.9.3 [ffi flutter flutter_web_plugins http image js meta pdf plugin_platform_interface]
- progress_dialog 1.2.4 [flutter]
- pull_to_refresh 2.0.0 [flutter]
- receive_sharing_intent 1.4.5 [flutter]
- reorderables 0.4.1 [flutter]
- scoped_model 1.1.0 [flutter]
- screenshot 1.2.3 [flutter]
- scrollable_positioned_list 0.1.7 [flutter meta]
- share_extend 2.0.0 [meta flutter]
- share_plus 3.0.4 [meta mime flutter share_plus_platform_interface share_plus_linux share_plus_macos share_plus_windows share_plus_web]
- shared_preferences 2.0.12 [flutter shared_preferences_android shared_preferences_ios shared_preferences_linux shared_preferences_macos shared_preferences_platform_interface shared_preferences_web shared_preferences_windows]
- sqflite 2.0.2 [flutter sqflite_common path]
- synchronized 3.0.0
- table_calendar 3.0.7 [flutter intl simple_gesture_detector]
- url_launcher 6.0.18 [flutter url_launcher_android url_launcher_ios url_launcher_linux url_launcher_macos url_launcher_platform_interface url_launcher_web url_launcher_windows]
- video_compress 3.1.1 [flutter]
- video_thumbnail 0.5.2 [flutter]

dev dependencies:
- change_app_package_name 1.0.0
- flutter_test 0.0.0 [flutter test_api path fake_async clock stack_trace vector_math async boolean_selector characters collection matcher material_color_utilities meta source_span stream_channel string_scanner term_glyph]

dependency overrides:
- firebase_core_platform_interface 4.5.1 [collection flutter flutter_test meta plugin_platform_interface]

transitive dependencies:
- _flutterfire_internals 1.0.5 [cloud_firestore_platform_interface cloud_firestore_web collection firebase_core firebase_core_platform_interface flutter meta]
- archive 3.3.1 [crypto path]
- args 2.3.1
- asn1lib 1.1.0
- async 2.9.0 [collection meta]
- barcode 2.2.1 [meta qr]
- boolean_selector 2.1.0 [source_span string_scanner]
- cached_network_image_platform_interface 1.0.0 [flutter flutter_cache_manager]
- cached_network_image_web 1.0.1 [flutter flutter_cache_manager cached_network_image_platform_interface]
- characters 1.2.1
- clock 1.1.1
- cloud_firestore_platform_interface 5.8.2 [_flutterfire_internals collection firebase_core flutter meta plugin_platform_interface]
- cloud_firestore_web 3.0.2 [_flutterfire_internals cloud_firestore_platform_interface collection firebase_core firebase_core_web flutter flutter_web_plugins js]
- collection 1.16.0
- connectivity_for_web 0.4.0+1 [connectivity_platform_interface flutter_web_plugins flutter]
- connectivity_macos 0.2.1+2 [flutter connectivity_platform_interface]
- connectivity_platform_interface 2.0.1 [flutter meta plugin_platform_interface]
- convert 3.0.2 [typed_data]
- cross_file 0.3.3+1 [js meta]
- crypto 3.0.2 [typed_data]
- csslib 0.17.2 [source_span]
- cupertino_icons 1.0.5
- device_info_plus_linux 3.0.0 [device_info_plus_platform_interface file flutter meta]
- device_info_plus_macos 3.0.0 [device_info_plus_platform_interface flutter]
- device_info_plus_platform_interface 3.0.0 [flutter meta plugin_platform_interface]
- device_info_plus_web 3.0.0 [device_info_plus_platform_interface flutter_web_plugins flutter]
- device_info_plus_windows 4.1.0 [device_info_plus_platform_interface ffi flutter win32]
- fake_async 1.3.1 [clock collection]
- ffi 2.0.1
- file 6.1.2 [meta path]
- firebase_auth_platform_interface 6.10.4 [_flutterfire_internals collection firebase_core flutter meta plugin_platform_interface]
- firebase_auth_web 5.0.2 [firebase_auth_platform_interface firebase_core firebase_core_web flutter flutter_web_plugins http_parser intl js meta]
- firebase_core_web 2.0.0 [firebase_core_platform_interface flutter flutter_web_plugins js meta]
- firebase_messaging_platform_interface 4.2.3 [_flutterfire_internals firebase_core flutter meta plugin_platform_interface]
- firebase_messaging_web 3.2.3 [_flutterfire_internals firebase_core firebase_core_web firebase_messaging_platform_interface flutter flutter_web_plugins js meta]
- firebase_storage_platform_interface 4.1.21 [collection firebase_core flutter meta plugin_platform_interface]
- firebase_storage_web 3.3.12 [_flutterfire_internals async firebase_core firebase_core_web firebase_storage_platform_interface flutter flutter_web_plugins http js meta]
- flutter_blurhash 0.7.0 [flutter]
- flutter_cache_manager 3.3.0 [clock collection file flutter http path path_provider pedantic rxdart sqflite uuid]
- flutter_custom_tabs_platform_interface 1.0.1 [flutter plugin_platform_interface meta]
- flutter_custom_tabs_web 1.0.0 [flutter flutter_web_plugins flutter_custom_tabs_platform_interface meta url_launcher_web url_launcher_platform_interface]
- flutter_keyboard_visibility 5.3.0 [meta flutter_keyboard_visibility_platform_interface flutter_keyboard_visibility_web flutter]
- flutter_keyboard_visibility_platform_interface 2.0.0 [flutter meta plugin_platform_interface]
- flutter_keyboard_visibility_web 2.0.0 [flutter_keyboard_visibility_platform_interface flutter_web_plugins flutter]
- flutter_plugin_android_lifecycle 2.0.7 [flutter]
- flutter_secure_storage_linux 1.1.0 [flutter flutter_secure_storage_platform_interface]
- flutter_secure_storage_macos 1.1.0 [flutter flutter_secure_storage_platform_interface]
- flutter_secure_storage_platform_interface 1.0.0 [flutter plugin_platform_interface]
- flutter_secure_storage_web 1.0.2 [flutter flutter_web_plugins flutter_secure_storage_platform_interface js]
- flutter_secure_storage_windows 1.1.2 [flutter flutter_secure_storage_platform_interface]
- flutter_web_plugins 0.0.0 [flutter js characters collection material_color_utilities meta vector_math]
- google_sign_in_android 6.1.0 [flutter google_sign_in_platform_interface]
- google_sign_in_ios 5.5.0 [flutter google_sign_in_platform_interface]
- google_sign_in_platform_interface 2.2.0 [flutter quiver]
- google_sign_in_web 0.10.2 [flutter flutter_web_plugins google_sign_in_platform_interface js]
- html 0.15.0 [csslib source_span]
- http_parser 4.0.1 [collection source_span string_scanner typed_data]
- image 3.1.3 [archive meta xml]
- image_picker_for_web 2.1.8 [flutter flutter_web_plugins image_picker_platform_interface]
- image_picker_platform_interface 2.6.1 [cross_file flutter http plugin_platform_interface]
- intl 0.17.0 [clock path]
- js 0.6.4
- matcher 0.12.12 [stack_trace]
- material_color_utilities 0.1.5
- meta 1.8.0
- mime 1.0.2
- nested 1.0.0 [flutter]
- octo_image 1.0.2 [flutter flutter_blurhash]
- path 1.8.2
- path_parsing 1.0.0 [vector_math meta]
- path_provider_android 2.0.17 [flutter path_provider_platform_interface]
- path_provider_ios 2.0.11 [flutter path_provider_platform_interface]
- path_provider_linux 2.1.7 [ffi flutter path path_provider_platform_interface xdg_directories]
- path_provider_macos 2.0.6 [flutter path_provider_platform_interface]
- path_provider_platform_interface 2.0.4 [flutter platform plugin_platform_interface]
- path_provider_windows 2.1.3 [ffi flutter path path_provider_platform_interface win32]
- pdf 3.8.2 [archive barcode crypto image meta path_parsing vector_math xml]
- pedantic 1.11.1
- permission_handler_android 10.0.0 [flutter permission_handler_platform_interface]
- permission_handler_apple 9.0.4 [flutter permission_handler_platform_interface]
- permission_handler_platform_interface 3.7.0 [flutter meta plugin_platform_interface]
- permission_handler_windows 0.1.0 [flutter permission_handler_platform_interface]
- petitparser 4.4.0 [meta]
- platform 3.1.0
- plugin_platform_interface 2.1.2 [meta]
- pointycastle 3.6.1 [collection convert js]
- process 4.2.4 [file path platform]
- provider 5.0.0 [collection flutter nested]
- qr 3.0.1 [meta]
- quiver 3.1.0 [matcher]
- rxdart 0.27.5
- share_plus_linux 2.0.4 [share_plus_platform_interface file flutter meta url_launcher]
- share_plus_macos 2.1.0 [share_plus_platform_interface flutter]
- share_plus_platform_interface 2.1.0 [flutter meta mime plugin_platform_interface]
- share_plus_web 2.0.4 [share_plus_platform_interface url_launcher flutter flutter_web_plugins meta]
- share_plus_windows 2.0.3 [share_plus_platform_interface flutter meta url_launcher]
- shared_preferences_android 2.0.12 [flutter shared_preferences_platform_interface]
- shared_preferences_ios 2.1.1 [flutter shared_preferences_platform_interface]
- shared_preferences_linux 2.1.1 [file flutter path path_provider_linux path_provider_platform_interface shared_preferences_platform_interface]
- shared_preferences_macos 2.0.4 [flutter shared_preferences_platform_interface]
- shared_preferences_platform_interface 2.0.0 [flutter]
- shared_preferences_web 2.0.4 [flutter flutter_web_plugins shared_preferences_platform_interface]
- shared_preferences_windows 2.1.1 [file flutter path path_provider_platform_interface path_provider_windows shared_preferences_platform_interface]
- simple_gesture_detector 0.2.0 [flutter]
- sky_engine 0.0.99
- source_span 1.9.0 [collection path term_glyph]
- sqflite_common 2.2.1+1 [synchronized path meta]
- stack_trace 1.10.0 [path]
- stream_channel 2.1.0 [async]
- string_scanner 1.1.1 [source_span]
- term_glyph 1.2.1
- test_api 0.4.12 [async boolean_selector collection meta source_span stack_trace stream_channel string_scanner term_glyph matcher]
- typed_data 1.3.0 [collection]
- url_launcher_android 6.0.17 [flutter url_launcher_platform_interface]
- url_launcher_ios 6.0.17 [flutter url_launcher_platform_interface]
- url_launcher_linux 2.0.3 [flutter]
- url_launcher_macos 2.0.3 [flutter]
- url_launcher_platform_interface 2.1.0 [flutter plugin_platform_interface]
- url_launcher_web 2.0.12 [flutter flutter_web_plugins url_launcher_platform_interface]
- url_launcher_windows 2.0.2 [flutter]
- uuid 3.0.6 [crypto]
- vector_math 2.1.2
- video_player 2.4.5 [flutter html video_player_android video_player_avfoundation video_player_platform_interface video_player_web]
- video_player_android 2.3.8 [flutter video_player_platform_interface]
- video_player_avfoundation 2.3.5 [flutter video_player_platform_interface]
- video_player_platform_interface 5.1.3 [flutter plugin_platform_interface]
- video_player_web 2.0.12 [flutter flutter_web_plugins video_player_platform_interface]
- wakelock 0.5.6 [flutter meta wakelock_macos wakelock_platform_interface wakelock_web wakelock_windows]
- wakelock_macos 0.4.0 [flutter flutter_web_plugins wakelock_platform_interface]
- wakelock_platform_interface 0.3.0 [flutter meta]
- wakelock_web 0.4.0 [flutter flutter_web_plugins js wakelock_platform_interface]
- wakelock_windows 0.2.0 [flutter wakelock_platform_interface win32]
- win32 2.7.0 [ffi]
- xdg_directories 0.2.0+1 [meta path process]
- xml 5.3.1 [collection meta petitparser]
- yaml 3.1.1 [collection source_span string_scanner]

---

[danagbemava-nc]

Hi @rignaneseleo, is this issue only on iOS, or are you also experiencing this issue on android?

If this is also on android, can you share the logs?

I tried the firebase_storage example code, which calls the methods you've referenced above and everything works as expected.

Can you share a complete minimal reproducible code sample as well?

[JavierPerezLavadie]

Hi, Maybe it's the same if you use the Firebase emulator

#9791

[JavierPerezLavadie]

it can help I think it's known bugs of the last version I should have waited before updating

firebase/firebase-ios-sdk#10374

[rignaneseleo]

It's ONLY on iOS. The issue is the same reported by Javier.

[danagbemava-nc]

I can reproduce the issue only when using the storage emulator.

FLTFirebaseStorage: An unknown error occurred while calling method Reference#getDownloadURL
[VERBOSE-2:dart_vm_initializer.cc(41)] Unhandled Exception: [firebase_storage/unknown] An unknown error occurred, please check the server response.
#0      StandardMethodCodec.decodeEnvelope
package:flutter/…/services/message_codecs.dart:653
#1      MethodChannel._invokeMethod
package:flutter/…/services/platform_channel.dart:296
<asynchronous suspension>
#2      MethodChannel.invokeMapMethod
package:flutter/…/services/platform_channel.dart:499
<asynchronous suspension>
#3      MethodChannelReference.getDownloadURL
package:firebase_storage_platform_interface/…/method_channel/method_channel_reference.dart:45
<asynchronous suspension>
#4      _TaskManager._downloadLink
package:triage/main.dart:162
<asynchronous suspension>

[danagbemava-nc]

/cc @russellwheatley, since this has been reported upstream, should we keep this open to track this here or close it in favor of the upstream issue?

[russellwheatley]

This has been fixed on the iOS SDK and will be part of the next release I believe: firebase/firebase-ios-sdk#10370

[rignaneseleo]

I'm now using the updated libraries:

  firebase_core: 2.1.1
  firebase_auth: 4.1.0
  firebase_storage: 11.0.3
  firebase_messaging: 14.0.3
  cloud_firestore: 4.0.3

But the problem still occurs (only on iOS):

FLTFirebaseStorage: An unknown error occurred while calling method Reference#getDownloadURL
flutter: error: Upload error: [firebase_storage/unknown] An unknown error occurred, please check the server response.

[jslattery26]

Same here. on my real device, iOS only. I realized that while having customMetadata

final metadata = SettableMetadata(
      customMetadata: {'owner': uid},
      contentType: file.mimeType,
    );
uploadTask = ref.putFile(File(file.path), metadata);

I get the error.. then after removing it..

final metadata = SettableMetadata(
      // customMetadata: {'owner': uid},
      contentType: file.mimeType,
    );
uploadTask = ref.putFile(File(file.path), metadata);

It works. can anyone confirm?

[duduBaiao]

This is happening to me as well, only on iOS.
I'm running it on a real device:

[+20953 ms] FLTFirebaseStorage: An unknown error occurred while calling method Reference#getDownloadURL
[        ] flutter: SEVERE: [firebase_storage/unknown] An unknown error occurred, please check the server response.
[        ] flutter: [firebase_storage/unknown] An unknown error occurred, please check the server response.
[        ] flutter: #0      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:653:7)
[        ] #1      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:296:18)
[        ] <asynchronous suspension>
[        ] #2      MethodChannel.invokeMapMethod (package:flutter/src/services/platform_channel.dart:499:43)
[        ] <asynchronous suspension>
[        ] #3      MethodChannelReference.getDownloadURL (package:firebase_storage_platform_interface/src/method_channel/method_channel_reference.dart:45:36)
[        ] <asynchronous suspension>
[        ] #4      RemoteStorageImpl._uploadFile.<anonymous closure> (package:storage/remote_storage.dart:76:31)

It worked when I removed the "customMetadata" key, as pointed out by @jslattery26 (tks for that!).

[russellwheatley]

The fix has been released in Firebase iOS SDK 10.1.0. I've created a PR to update.

[rignaneseleo]

Thanks @russellwheatley
Any way I can use this fix before the merge?

[russellwheatley]

Update this file: https://github.com/firebase/flutterfire/blob/master/packages/firebase_core/firebase_core/ios/firebase_sdk_version.rb#L3

[cyberpwnn]

Is this merged yet?

[rignaneseleo]

Is this merged yet?

I think so! It's in release

[isAlmogK]

Has this fix been released?