这是怎么回事？只是打开过 monkeyrunner 而已后报错？
org.openqa.selenium.SessionNotCreatedException: A new session could not be created. (Original error: UiAutomator quit before it successfully launched) (WARNING: The server did not provide any stacktrace information)
Command duration or timeout: 6.59 seconds
Build info: version: '2.41.0', revision: '3192d8a6c4449dc285928ba024779344f5423c58', time: '2014-03-27 11:29:39'
System info: host: 'sam-PC', ip: '192.168.0.211', os.name: 'Windows 7', os.arch: 'amd64', os.version: '6.1', java.version: '1.7.0_25'
Driver info: com.myappiumtest.app.myapp.AndroidContactsTest$SwipeableWebDriver
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at org.openqa.selenium.remote.ErrorHandler.createThrowable(ErrorHandler.java:193)
at org.openqa.selenium.remote.ErrorHandler.throwIfResponseFailed(ErrorHandler.java:145)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:595)
at org.openqa.selenium.remote.RemoteWebDriver.startSession(RemoteWebDriver.java:240)
at org.openqa.selenium.remote.RemoteWebDriver.(RemoteWebDriver.java:126)
at org.openqa.selenium.remote.RemoteWebDriver.(RemoteWebDriver.java:153)
at com.myappiumtest.app.myapp.AndroidContactsTest$SwipeableWebDriver.(AndroidContactsTest.java:27)
at com.myappiumtest.app.myapp.AndroidContactsTest.setUp(AndroidContactsTest.java:90)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:24)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
java.lang.NullPointerException
at com.myappiumtest.app.myapp.AndroidContactsTest.tearDown(AndroidContactsTest.java:95)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:33)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
我也遇到了，我知道是什么问题，手机端的 uiautomator 端口被占用了，adb shell ps 杀一下进程就好，或者重启一下手机
请问你最后是怎么解决的，我也遇到了同样的问题。
这是我的报错截图，请帮我看看，谢谢！
二月 22, 2017 5:07:17 下午 org.openqa.selenium.remote.ProtocolHandshake createSession
信息: Attempting bi-dialect session, assuming Postel's Law holds true on the remote end
Exception in thread "main" org.openqa.selenium.SessionNotCreatedException: A new session could not be created. (Original error: UiAutomator quit before it successfully launched) (WARNING: The server did not provide any stacktrace information)
Command duration or timeout: 0 milliseconds
Build info: version: '3.0.1', revision: '1969d75', time: '2016-10-18 09:48:19 -0700'
System info: host: 'PC201403181853', ip: '113.250.156.78', os.name: 'Windows 7', os.arch: 'amd64', os.version: '6.1', java.version: '1.8.0_111'
Driver info: driver.version: AndroidDriver