Android Studio で Build ができない。

Buildを行うとこんな感じ。
とりあえず、回避。

Executing tasks: [clean, :app:assembleDebug] in project C:\Users\xxxx\AndroidStudioProjects\MyApplication

Build-tool 31.0.0 is missing DX at C:\Users\xxxx\AppData\Local\Android\Sdk\build-tools\31.0.0\dx.bat
Build-tool 31.0.0 is missing DX at C:\Users\xxxx\AppData\Local\Android\Sdk\build-tools\31.0.0\dx.bat

FAILURE: Build failed with an exception.

* What went wrong:
Could not determine the dependencies of task ':app:compileDebugJavaWithJavac'.
> Installed Build Tools revision 31.0.0 is corrupted. Remove and install again using the SDK Manager.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 2s

Tools - SDK Manager
から
SDK Platforms
で以下をチェック

• Android 11.0(R)
• Android 10.0(Q)
• Android 9.0(Pie)

SDK Tools
で
Show Package Details
にチェックをつけて
以下をチェック

Android SDK Build-Tools 31

• 31.0.0
• 30.0.3
• 29.0.3
• 28.0.3
• 27.0.3

以下のファイルを修正

.\app\build.gradle

  android {
    compileSdkVersion 30 <<<
    buildToolsVersion "30.0.3" <<<

    defaultConfig {
        applicationId "com.example.myapplication"
        minSdkVersion 19
        targetSdkVersion 30 <<<

Build - Rebuild Project
を実行