title: Android Studio 3.0.1 Error: Gradle project sync failed. Basic functionality (e.g. editing, debugging) will not work properly
body: <p>I've installed Android studio 3.0.1 then tried to build very first app by choosing an empty activity, but I've got this message:</p>
  <blockquote>
  <p>Gradle project sync failed. Basic functionality (e.g. editing, debugging) will not work properly</p>
  </blockquote>
  <p>and the error message like this:</p>
  <blockquote>
  <p>Unable to resolve dependency for ':app@releaseUnitTest/compileClasspath': Could not resolve com.android.support:appcompat-v7:26.1.0.
  Could not resolve com.android.support:appcompat-v7:26.1.0.
  Required by:
  project :app
  Could not resolve com.android.support:appcompat-v7:26.1.0.
  &gt; Could not parse POM <a href="https://dl.google.com/dl/android/maven2/com/android/support/appcompat-v7/26.1.0/appcompat-v7-26.1.0.pom" rel="nofollow noreferrer">https://dl.google.com/dl/android/maven2/com/android/support/appcompat-v7/26.1.0/appcompat-v7-26.1.0.pom</a>
  &gt; Already seen doctype.</p>
  </blockquote>
  <p><a href="https://i.stack.imgur.com/6JZKe.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/6JZKe.png" alt="enter image description here" /></a></p>
  <p><a href="https://i.stack.imgur.com/sAxvL.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/sAxvL.png" alt="enter image description here" /></a></p>
  <p>The first part of log message is like this:</p>
  <blockquote>
  <p>2018-01-03 11:11:12,671 [d thread 8]   WARN - ect.sync.idea.ProjectSetUpTask - Already seen doctype.
  Consult IDE log for more details (Help | Show Log)
  2018-01-03 11:11:12,671 [d thread 8]   INFO - e.project.sync.GradleSyncState - Gradle sync failed: Already seen doctype.</p>
  </blockquote>
  <p>I've tried some suggested solutions like changing gradle version, update Kotlin plugin(!) and so, but they didn't work.</p>
  <p>Any solution?</p>