مشكل در اجراى برنامه

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Launching lib\main.dart on sdk gphone x86 arm
in debug mode...
Running Gradle task 'assembleDebug'...
[Fatal Error] gradle-3.5.0.pom:2:1: Content is not allowed in prolog.
[Fatal Error] kotlin-gradle-plugin-1.3.50.pom:2:1: Content is not allowed in prolog.

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:3.5.0.
  Required by:
  project :
  Could not resolve com.android.tools.build:gradle:3.5.0.
  Could not parse POM https://dl.google.com/dl/android/maven2/com/android/tools/build/gradle/3.5.0/gradle-3.5.0.pom
  Content is not allowed in prolog.
  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 parse POM https://jcenter.bintray.com/org/jetbrains/kotlin/kotlin-gradle-plugin/1.3.50/kotlin-gradle-plugin-1.3.50.pom
  Content is not allowed in prolog.

• 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
Finished with error: Gradle task assembleDebug failed with exit code 1