Flutter调试：等待调试连接时出错：错误的状态：无元素

尝试在Flutter中调试新创建的项目时出现错误。这是错误之前的LOG。

[   +1 ms] executing: C:\Users\pfernandes\AppData\Local\Android\sdk\platform-tools\adb.exe -s 0123456789ABCDEF shell am start -a android.intent.action.RUN -f 0x20000000 --ez enable-background-compilation true --ez enable-dart-profiling true --ez enable-checked-mode true --ez verify-entry-points true --ez start-paused true com.mycompany.my_app_pos_payment_app/com.mycompany.my_app_pos_payment_app.MainActivity
[ +696 ms] Starting: Intent { act=android.intent.action.RUN flg=0x20000000 cmp=com.mycompany.my_app_pos_payment_app/.MainActivity (has extras) }
[        ] Waiting for observatory port to be available...
[   +4 ms] Error waiting for a debug connection: Bad state: No element
[        ] Error launching application on N910.

我可以毫无问题地调试纯Android项目。

这是我扑扑的医生：

[√] Flutter (Channel master, v1.14.7-pre.45, on Microsoft Windows [Version 10.0.17763.914], locale en-US)
    • Flutter version 1.14.7-pre.45 at c:\sdk\flutter
    • Framework revision 9375377fa9 (2 hours ago), 2020-01-30 09:36:41 -0800
    • Engine revision f6526c0cf8
    • Dart version 2.8.0 (build 2.8.0-dev.6.0 fc3af737c7)

[√] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
    • Android SDK at C:\Users\pfernandes\AppData\Local\Android\sdk
    • Android NDK location not configured (optional; useful for native profiling support)
    • Platform android-29, build-tools 29.0.2
    • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b03)
    • All Android licenses accepted.

[√] Android Studio (version 3.5)
    • Android Studio at C:\Program Files\Android\Android Studio
    • Flutter plugin version 42.1.1
    • Dart plugin version 191.8593
    • Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b03)

[√] VS Code, 64-bit edition (version 1.41.1)
    • VS Code at C:\Program Files\Microsoft VS Code
    • Flutter extension version 3.7.1

[√] Connected device (1 available)
    • N910 • 0123456789ABCDEF • android-arm • Android 5.1.1 (API 22)

• No issues found!