Flutter: «Не удалось разрешить все артефакты для конфигурации ': classpath'»

Question

Я пытаюсь запустить приложение флаттера по умолчанию, но когда я запускаю, оно дает следующую ошибку:

Running Gradle task 'assembleDebug'...

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring root project 'android'.
> Could not resolve all artifacts for configuration ':classpath'.
   > Could not resolve com.android.tools.build:gradle:3.5.3.
     Required by:
         project :
      > Could not resolve com.android.tools.build:gradle:3.5.3.
         > Could not get resource 'https://dl.google.com/dl/android/maven2/com/android/tools/build/gradle/3.5.3/gradle-3.5.3.pom'.
            > Could not GET 'https://dl.google.com/dl/android/maven2/com/android/tools/build/gradle/3.5.3/gradle-3.5.3.pom'.
               > Connect to 172.30.0.15:3128 [/172.30.0.15] failed: Connection timed out: connect
      > Could not resolve com.android.tools.build:gradle:3.5.3.
         > Could not get resource 'https://jcenter.bintray.com/com/android/tools/build/gradle/3.5.3/gradle-3.5.3.pom'.
            > Could not GET 'https://jcenter.bintray.com/com/android/tools/build/gradle/3.5.3/gradle-3.5.3.pom'.
               > Connect to 172.30.0.15:3128 [/172.30.0.15] failed: Connection timed out: connect
   > Could not resolve org.jetbrains.kotlin:kotlin-gradle-plugin:1.3.50.
     Required by:
         project :
      > Could not resolve org.jetbrains.kotlin:kotlin-gradle-plugin:1.3.50.
         > Could not get resource 'https://dl.google.com/dl/android/maven2/org/jetbrains/kotlin/kotlin-gradle-plugin/1.3.50/kotlin-gradle-plugin-1.3.50.pom'.
            > Could not GET 'https://dl.google.com/dl/android/maven2/org/jetbrains/kotlin/kotlin-gradle-plugin/1.3.50/kotlin-gradle-plugin-1.3.50.pom'.
               > Connect to 172.30.0.15:3128 [/172.30.0.15] failed: Connection timed out: connect
      > Could not resolve org.jetbrains.kotlin:kotlin-gradle-plugin:1.3.50.
         > Could not get resource 'https://jcenter.bintray.com/org/jetbrains/kotlin/kotlin-gradle-plugin/1.3.50/kotlin-gradle-plugin-1.3.50.pom'.
            > Could not GET 'https://jcenter.bintray.com/org/jetbrains/kotlin/kotlin-gradle-plugin/1.3.50/kotlin-gradle-plugin-1.3.50.pom'.
               > Connect to 172.30.0.15:3128 [/172.30.0.15] failed: Connection timed out: connect

* 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 2m 25s
Exception: Gradle task assembleDebug failed with exit code 1

ниже код build.gradle:

buildscript {
    ext.kotlin_version = '1.3.50'
    repositories {
        google()
        jcenter()
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:3.5.3'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

rootProject.buildDir = '../build'
subprojects {
    project.buildDir = "${rootProject.buildDir}/${project.name}"
}
subprojects {
    project.evaluationDependsOn(':app')
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

Весь код приложения по умолчанию, никаких изменений не было. Я только что подключил эмулятор и попытался запустить его, если он работает, но застрял на этой ошибке buildDebug. Если у кого-то есть идеи, где я ошибаюсь, прокомментируйте ...