Install help

This page describes some common installation issues new Flutter users have encountered and offers suggestions on how to resolve them. If you are still experiencing problems, consider reaching out to any of the resources listed under community support channels. To add a topic to this page or make a correction, you can file an issue or a pull request using the buttons at the top of the page.

What does this issue look like?

When you try to run the flutter command, the console fails to find it. The error usually looks as follows:

'flutter' is not recognized as an internal or external command operable program or batch file

Error messages on macOS and Linux could look slightly different from the one on Windows.

Explanation and suggestions

Did you add Flutter to the PATH environment variable for your platform? On Windows, follow these instructions for adding a command to your path.

If you've already set up VS Code for Flutter development, you can use the Flutter extension's Locate SDK prompt to identify the location of your flutter folder.

See also: Configuring PATH and Environment Variables - Dart Code

What does this issue look like?

Running your Flutter project produces an error like the following:

The Flutter SDK is installed in a protected folder and may not function correctly.
Please move the SDK to a location that is user-writable without Administration permissions and restart.

Explanation and suggestions

On Windows, this usually happens when Flutter is installed in a directory like C:\Program Files\ that requires elevated privileges. Try relocating Flutter to a different folder, such as C:\src\flutter.

What does this issue look like?

The command flutter doctor --android-licenses fails. Running flutter doctor –verbose gives an error message like the following:

java.lang.UnsupportedClassVersionError: com/android/prefs/AndroidLocationsProvider 
has been compiled by a more recent version of the Java Runtime (class file version 55.0), 
this version of the Java Runtime only recognizes class file versions up to 52.0

Explanation and suggestions

The error occurs when an older version of the Java Development Kit (JDK) is installed on your computer.

If you don't need multiple versions of Java, uninstall existing JDKs from your computer. Flutter automatically uses the JDK included in Android Studio.

If you do need another version of Java, try the workaround described in this GitHub issue until a long-term solution is implemented. For more information, check out the Android Java Gradle migration guide or flutter doctor --android-licenses not working due to java.lang.UnsupportedClassVersionError - Stack Overflow.

What does this issue look like?

The flutter doctor command complains that the cmdline-tools are missing from the Android toolchain. For example:

[!] Android toolchain - develop for Android devices (Android SDK version 33.0.2) 
    • Android SDK at C:\Users\My PC\AppData\Local\Android\sdk 
    X cmdline-tools component is missing

Explanation and suggestions

The easiest way to get the cmdline-tools is through the SDK Manager in Android Studio. To do this, use the following instructions:

1. Open the SDK Manager from Android Studio, by selecting Tools > SDK Manager from the menu bar.
2. Select the latest Android SDK (or a specific version that your app requires), Android SDK Command-line Tools, and Android SDK Build-Tools.
3. Click Apply to install the selected artifacts.

If you're not using Android Studio, you can download the tools using the sdkmanager command-line tool.

What does this issue look like?

Running a flutter command produces an "exit code: 69" error, as shown in the following example:

Running "flutter pub get" in flutter_tools...
Resolving dependencies in .../flutter/packages/flutter_tools... (28.0s)
Got TLS error trying to find package test at https://pub.dev/.
pub get failed
command:
".../flutter/bin/cache/dart-sdk/bin/
dart __deprecated_pub --color --directory
.../flutter/packages/flutter_tools get --example"
pub env: {
  "FLUTTER_ROOT": ".../flutter",
  "PUB_ENVIRONMENT": "flutter_cli:get",
  "PUB_CACHE": ".../.pub-cache",
}
exit code: 69

Explanation and suggestions

This issue is related to networking. Try the following instructions to troubleshoot:

• Check your internet connection. Make sure that you are connected to the internet and that your connection is stable.
• Restart your devices, including your computer and networking equipment.
• Use a VPN to help to bypass any restrictions that might prevent you from connecting to the network.
• If you have tried all of these steps and are still getting the error, print out verbose logs with the flutter doctor -v command and ask for help in one of the community support channels.

The Flutter community is helpful and welcoming. If none of the above suggestions solves your installation issue, consider asking for support from one of the following channels:

• /r/flutterhelp on Reddit
• /r/flutterdev on Discord, particularly the install-and-setup channel on this server.
• StackOverflow, in particular, questions tagged with #flutter or #dart.

除非另有说明，本文档之所提及适用于 Flutter 的最新稳定版本，本页面最后更新时间: 2024-04-04。 查看文档源码 或者 为本页面内容提出建议。