更新android sdk后，在构建项目时会遇到一个混乱的错误。
这是一个导入的eclipse项目，我所做的是安装了SDK 26和build-tools 26，卸载了旧的SDK 15-18和build-tools 25.0.2。
我尝试重新安装这些东西，但不行。
以下是错误消息：
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.<init>(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)