appium+java 对 ios 进行自动化时，使用 click 操作时报错，使用 tap 也会报一样的错（都是同一个错误），折磨好久了，百度了各种资料都不行，实在没办法了才来提问题，谢谢大家了。以下是报错信息：

FAILED: f
org.openqa.selenium.WebDriverException: An unknown server-side error occurred while processing the command. Original error: An error occurred (WARNING: The server did not provide any stacktrace information)
Command duration or timeout: 0 milliseconds
Build info: version: '3.14.0', revision: 'aacccce0', time: '2018-08-02T20:19:58.91Z'
System info: host: 'lcMac.local', ip: '169.254.126.164', os.name: 'Mac OS X', os.arch: 'x86_64', os.version: '10.13.2', java.version: '1.8.0_181'
Driver info: io.appium.java_client.ios.IOSDriver
Capabilities {automationName: XCUITest, browserName: , bundleId: com.jgrm1041.XCTestDemo, databaseEnabled: false, deviceName: iPhone 7, javascriptEnabled: true, locationContextEnabled: false, networkConnectionEnabled: false, noReset: true, platform: MAC, platformName: MAC, platformVersion: 11.3, takesScreenshot: true, udid: 94ccfe0bc034d610d2119536bfa..., webStorageEnabled: false}
Session ID: 46f14ebf-3118-4d9a-89d2-535a40936a90
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
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.http.JsonHttpResponseCodec.reconstructValue(JsonHttpResponseCodec.java:40)
at org.openqa.selenium.remote.http.AbstractHttpResponseCodec.decode(AbstractHttpResponseCodec.java:80)
at org.openqa.selenium.remote.http.AbstractHttpResponseCodec.decode(AbstractHttpResponseCodec.java:44)
at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:158)
at io.appium.java_client.remote.AppiumCommandExecutor.execute(AppiumCommandExecutor.java:89)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:548)
at io.appium.java_client.DefaultGenericMobileDriver.execute(DefaultGenericMobileDriver.java:46)
at io.appium.java_client.AppiumDriver.execute(AppiumDriver.java:1)
at io.appium.java_client.ios.IOSDriver.execute(IOSDriver.java:1)
at io.appium.java_client.HasSessionDetails.getSessionDetails(HasSessionDetails.java:38)
at io.appium.java_client.HasSessionDetails.getSessionDetail(HasSessionDetails.java:55)
at io.appium.java_client.HasSessionDetails.getAutomationName(HasSessionDetails.java:71)
at io.appium.java_client.internal.ElementMap.getElementClass(ElementMap.java:79)
at io.appium.java_client.internal.JsonToMobileElementConverter.newMobileElement(JsonToMobileElementConverter.java:85)
at io.appium.java_client.internal.JsonToMobileElementConverter.apply(JsonToMobileElementConverter.java:66)
at com.google.common.collect.Iterators$6.transform(Iterators.java:788)
at com.google.common.collect.TransformedIterator.next(TransformedIterator.java:47)
at com.google.common.collect.Iterators.addAll(Iterators.java:358)
at com.google.common.collect.Lists.newArrayList(Lists.java:147)
at com.google.common.collect.Lists.newArrayList(Lists.java:133)
at io.appium.java_client.internal.JsonToMobileElementConverter.apply(JsonToMobileElementConverter.java:61)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:557)
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.ios.IOSDriver.execute(IOSDriver.java:1)
at org.openqa.selenium.remote.RemoteWebDriver.findElements(RemoteWebDriver.java:349)
at io.appium.java_client.DefaultGenericMobileDriver.findElements(DefaultGenericMobileDriver.java:54)
at io.appium.java_client.AppiumDriver.findElements(AppiumDriver.java:149)
at io.appium.java_client.FindsByAccessibilityId.findElementsByAccessibilityId(FindsByAccessibilityId.java:38)
at io.appium.java_client.AppiumDriver.findElementsByAccessibilityId(AppiumDriver.java:185)
at tngTest.NewTest.f(NewTest.java:49)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:108)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:661)
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:869)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1193)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:126)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:109)
at org.testng.TestRunner.privateRun(TestRunner.java:744)
at org.testng.TestRunner.run(TestRunner.java:602)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:380)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:375)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:340)
at org.testng.SuiteRunner.run(SuiteRunner.java:289)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1301)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1226)
at org.testng.TestNG.runSuites(TestNG.java:1144)
at org.testng.TestNG.run(TestNG.java:1115)
at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:114)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:251)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:77)

===============================================
Default test

Tests run: 1, Failures: 1, Skips: 0

===============================================
Default suite

Total tests run: 1, Failures: 1, Skips: 0