Error when uploading event: Value missing_event

[andriusscale]

Expected Behavior

Event should have been sent and show up in the events list.

Current Behavior

Amplitude SDK throws this error:

E/Amplitude(12281): Stack trace: org.json.JSONException: Value missing_event of type java.lang.String cannot be converted to JSONObject
E/Amplitude(12281): 	at org.json.JSON.typeMismatch(JSON.java:112)
E/Amplitude(12281): 	at org.json.JSONObject.<init>(JSONObject.java:172)
E/Amplitude(12281): 	at org.json.JSONObject.<init>(JSONObject.java:185)
E/Amplitude(12281): 	at com.amplitude.core.utilities.HttpResponse.createHttpResponse(Response.kt:14)
E/Amplitude(12281): 	at com.amplitude.core.utilities.HttpClient$upload$1.close(HttpClient.kt:40)
E/Amplitude(12281): 	at com.amplitude.core.platform.EventPipeline$upload$1.invokeSuspend(EventPipeline.kt:142)
E/Amplitude(12281): 	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
E/Amplitude(12281): 	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:108)
E/Amplitude(12281): 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
E/Amplitude(12281): 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:644)
E/Amplitude(12281): 	at java.lang.Thread.run(Thread.java:1012)

No events appear in the amplitude website

Steps to Reproduce

1. Setup Amplitude

final amplitude = Amplitude(
    Configuration(
      apiKey: const String.fromEnvironment('AMPLITUDE_API_KEY'),
      serverUrl: 'https://api.eu.amplitude.com',
      serverZone: ServerZone.eu,
      defaultTracking: DefaultTrackingOptions.all(),
      logLevel: LogLevel.debug,
    ),
  );

2. Send a new event on Android
   amplitude.track(BaseEvent('event'));

Environment

amplitude_flutter:
version: "4.0.0-beta.5"
com.amplitude:analytics-android:1.19.1

[✓] Flutter (Channel stable, 3.24.4, on macOS 15.1)
• Flutter version 3.24.4 on channel stable
• Upstream repository https://github.com/flutter/flutter.git
• Framework revision 603104015d (3 weeks ago), 2024-10-24 08:01:25 -0700
• Engine revision db49896cf2
• Dart version 3.5.4
• DevTools version 2.37.3

[✓] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
• Platform android-34, build-tools 34.0.0
• Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 17.0.11+0-17.0.11b1207.24-11852314)
• All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 16.1)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Build 16B40
• CocoaPods version 1.16.2

[✓] Chrome - develop for the web
• Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2024.1)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/9212-flutter
• Dart plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/6351-dart
• Java version OpenJDK Runtime Environment (build 17.0.11+0-17.0.11b1207.24-11852314)

[✓] VS Code (version 1.95.2)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension version 3.100.0

[✓] Connected device (6 available)
• A142 (mobile) • android-arm64 • Android 14 (API 34)

[✓] Network resources
• All expected network resources are available.

[andriusscale]

Same issue with iOS, logs are getting spammed with this:

Error: Response failed with code400: missing_event
Error: Response failed with code400: missing_event
Error: Response failed with code400: missing_event
Error: Response failed with code400: missing_event