title: Imported eclipse project error after updating android sdk
body: <p>After updating android sdk, encounter a confused error when building my project.</p>
  
  <p>It is a imported eclipse project, what I did is installed SDK 26 and build-tools 26, uninstalled old SDK 15-18 and build-tools 25.0.2.</p>
  
  <p>I try to reinstall these things, but not work.</p>
  
  <p>Here is the error message:</p>
  
  <pre><code>Error:Internal error: (java.lang.ClassNotFoundException) com.android.prefs.AndroidLocation$AndroidLocationException
  java.lang.ClassNotFoundException: com.android.prefs.AndroidLocation$AndroidLocationException
      at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
      at org.jetbrains.jps.android.AndroidJpsUtil.getAndroidTarget(AndroidJpsUtil.java:404)
      at org.jetbrains.jps.android.AndroidJpsUtil.getAndroidPlatform(AndroidJpsUtil.java:480)
      at org.jetbrains.jps.android.builder.AndroidPreDexBuildTarget.computeRootDescriptors(AndroidPreDexBuildTarget.java:110)
      at org.jetbrains.jps.builders.impl.BuildRootIndexImpl.addRoots(BuildRootIndexImpl.java:72)
      at org.jetbrains.jps.builders.impl.BuildRootIndexImpl.&lt;init&gt;(BuildRootIndexImpl.java:62)
      at org.jetbrains.jps.cmdline.BuildRunner.load(BuildRunner.java:84)
      at org.jetbrains.jps.cmdline.BuildSession.runBuild(BuildSession.java:267)
      at org.jetbrains.jps.cmdline.BuildSession.run(BuildSession.java:125)
      at org.jetbrains.jps.cmdline.BuildMain$MyMessageHandler.lambda$channelRead0$0(BuildMain.java:236)
      at org.jetbrains.jps.cmdline.BuildMain$MyMessageHandler$$Lambda$4/71020844.run(Unknown Source)
      at org.jetbrains.jps.service.impl.SharedThreadPoolImpl.lambda$executeOnPooledThread$0(SharedThreadPoolImpl.java:42)
      at org.jetbrains.jps.service.impl.SharedThreadPoolImpl$$Lambda$2/1522311648.run(Unknown Source)
      at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
      at java.util.concurrent.FutureTask.run(FutureTask.java:266)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
      at java.lang.Thread.run(Thread.java:745)
  </code></pre>