Android Studio错误：未知主机

Question

我知道这已被多次询问，但我找不到合适的解决方案。

我将我的Android工作室从2.3.3更新为3.0.1。 然后我开始面对这个错误。

Unknown host 'This is usually a temporary error during hostname resolution and means that the local server did not receive a response from an authoritative server'. You may need to adjust the proxy settings in Gradle.

Enable Gradle 'offline mode' and sync project

Learn about configuring HTTP proxies in Gradle

当我点击“启用离线模式”时，出现以下错误：

Error:No cached version of com.android.tools.build:gradle:4.2.1 available for offline mode.
Disable Gradle 'offline mode' and sync project

我尝试设置代理，并尝试在离线模式下使用它。我甚至使用过VPN并尝试绕过代理，但它无法正常工作。