An unknown server-side error occurre while processing the command的解决办法
使用版本：
appium：1.6.5
java-client ：5.0.0
selenium：3.8.1
jdk：1.8
sdk：5.1.1
错误：
.EE
Time: 0.984
There were 2 errors:
1) PreQuestion(com.test.quiz.QuizTest)org.openqa.selenium.WebDriverException: An unknown server-side error occurred while processing the command. Original error: Unable to find an active device or emulator with OS 22. The following are available: emulator-5554 (5.1.1) (WARNING: The server did not provide any stacktrace information)
Command duration or timeout: 408 milliseconds
Build info: version: '3.8.1', revision: '6e95a6684b', time: '2017-12-01T19:05:32.194Z'
System info: host: 'DESKTOP-LBEOOIF', ip: '192.168.0.211', os.name: 'Windows 10', os.arch: 'x86', os.version: '10.0', java.version: '1.8.0_131'
Driver info: driver.version: AndroidDriver
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at org.openqa.selenium.remote.ErrorHandler.createThrowable(ErrorHandler.java:214)
at org.openqa.selenium.remote.ErrorHandler.throwIfResponseFailed(ErrorHandler.java:166)
at org.openqa.selenium.remote.JsonWireProtocolResponse.lambda$new$0(JsonWireProtocolResponse.java:53)
at org.openqa.selenium.remote.JsonWireProtocolResponse.lambda$getResponseFunction$2(JsonWireProtocolResponse.java:91)
at org.openqa.selenium.remote.ProtocolHandshake.lambda$createSession$0(ProtocolHandshake.java:123)
at java.util.stream.ReferencePipeline$3$1.accept(Unknown Source)
at java.util.Spliterators$ArraySpliterator.tryAdvance(Unknown Source)
at java.util.stream.ReferencePipeline.forEachWithCancel(Unknown Source)
at java.util.stream.AbstractPipeline.copyIntoWithCancel(Unknown Source)
at java.util.stream.AbstractPipeline.copyInto(Unknown Source)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source)
at java.util.stream.FindOps$FindOp.evaluateSequential(Unknown Source)
at java.util.stream.AbstractPipeline.evaluate(Unknown Source)
at java.util.stream.ReferencePipeline.findFirst(Unknown Source)
at org.openqa.selenium.remote.ProtocolHandshake.createSession(ProtocolHandshake.java:126)
at org.openqa.selenium.remote.ProtocolHandshake.createSession(ProtocolHandshake.java:73)
at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:142)
at io.appium.java_client.remote.AppiumCommandExecutor.execute(AppiumCommandExecutor.java:89)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:601)
at io.appium.java_client.DefaultGenericMobileDriver.execute(DefaultGenericMobileDriver.java:42)
at io.appium.java_client.AppiumDriver.execute(AppiumDriver.java:1)
at io.appium.java_client.android.AndroidDriver.execute(AndroidDriver.java:1)
at org.openqa.selenium.remote.RemoteWebDriver.startSession(RemoteWebDriver.java:219)
at org.openqa.selenium.remote.RemoteWebDriver.
at io.appium.java_client.DefaultGenericMobileDriver.
at io.appium.java_client.AppiumDriver.
at io.appium.java_client.AppiumDriver.
at io.appium.java_client.android.AndroidDriver.
at com.test.quiz.QuizTest.setUp(QuizTest.java:50)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:27)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31)
at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at junit.framework.JUnit4TestAdapter.run(JUnit4TestAdapter.java:39)
at com.test.result.TestSuit.main(TestSuit.java:23)
2) PreQuestion(com.test.quiz.QuizTest)java.lang.NullPointerException
at com.test.quiz.QuizTest.tearDown(QuizTest.java:87)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:37)
at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at junit.framework.JUnit4TestAdapter.run(JUnit4TestAdapter.java:39)
at com.test.result.TestSuit.main(TestSuit.java:23)
FAILURES!!!
Tests run: 1, Failures: 0, Errors: 2
解决办法：
问题引起的原因是platformVersion写成了22 API的级别了，将platformVersion改为5.1.1即可解决
