The output of

 flutter doctor


> Doctor summary (to see all details, run flutter doctor -v): [√]
> Flutter (Channel master, 2.1.0-13.0.pre.288, on Microsoft Windows
> [Version 10.0.19042.867], locale ) [!] Android toolchain - develop for
> Android devices (Android SDK version 29.0.2)
>     X Android SDK file not found: C:\Users\ASUS\AppData\Local\Android\sdk\platforms\android-29\android.jar.
> [√] Chrome - develop for the web [!] Visual Studio - develop for
> Windows (Visual Studio Community 2019 16.9.2)
>     X The current Visual Studio installation is incomplete. Please reinstall Visual Studio. [√] Android Studio (version 4.1.0) [√] VS
> Code (version 1.54.3) [√] Connected device (3 available

** Is there a solution to this problem?

Solution 1: Huthaifa Muayyad

There always is a solution. The path you are currently using isn't the path to the SDK, it's a path to the jar file. Android\sdk\platforms\android-29\android.jar.

Use flutter config --android-sdk <path-to-your-android-sdk-path>

Most likely for you it'll be

flutter config --android-sdk "C:\Users\ASUS\AppData\Local\Android\sdk"

Solution 2: Sanjar Elamonov

in order to solve the problem of android toolchain—> install the latest API from the SDK platforms in Settings.

If Android Toolchain showing the problem of 32, install Android API 32, if other version, install the one with that version.

Its probably the easiest way

Solution 3: user20067618

just delete android 29 and again run the application, it install again android 29 by it's self and it works properly