java-client: can't find element when use 5.0.0 beta1,wrong:"java.lang.ClassCastException: org.openqa.selenium.remote.RemoteWebElement cannot be cast to io.appium.java_client.MobileElement"

Description

when I use 5.0.0beta1 java-client,I can’t find any element.the wrong is:

java.lang.ClassCastException: org.openqa.selenium.remote.RemoteWebElement cannot be cast to io.appium.java_client.MobileElement

Environment

• java client build version or git revision if you use some shapshot:5.0.0 beta1 from maven
• Appium server version or git revision if you use some shapshot:1.6.0 and 1.6.3
• Mobile platform/version under test:ios 10.2,xcode 8.2.1
• Real device or emulator/simulator:real

Details

public class Test {

	private IOSDriver<MobileElement> driver = null;

	@BeforeClass
	public void beforeclass() {
		DesiredCapabilities capabilities = new DesiredCapabilities();
		capabilities.setCapability(MobileCapabilityType.PLATFORM_NAME, "IOS"); 
		capabilities.setCapability(MobileCapabilityType.AUTOMATION_NAME, "XCUITest"); 
		capabilities.setCapability(MobileCapabilityType.DEVICE_NAME, "111"); 
		capabilities.setCapability(MobileCapabilityType.APP, "my app"); 
		capabilities.setCapability(MobileCapabilityType.UDID, "my udid"); 

		try {
			driver = new IOSDriver<MobileElement>(new URL("http://127.0.0.1:4723/wd/hub"), capabilities);
		} catch (MalformedURLException e) {
			e.printStackTrace();
		}
	}

	@Test
	public void element() throws InterruptedException {
		Thread.sleep(10000);
		MobileElement element = (MobileElement) driver.findElement(By.className("XCUIElementTypeScrollView"));
		element.getSize();
		Thread.sleep(10000);
	}

	@AfterClass(alwaysRun = true)
	public void afterclass() {
		driver.quit();
	}
}

Ecxeption stacktraces

FAILED: element
java.lang.ClassCastException: org.openqa.selenium.remote.RemoteWebElement cannot be cast to io.appium.java_client.MobileElement
	at com.haimi.HMLibrary.keywords.swipeTest.element(swipeTest.java:52)
	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:497)
	at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:84)
	at org.testng.internal.Invoker.invokeMethod(Invoker.java:714)
	at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:901)
	at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1231)
	at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:127)
	at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:111)
	at org.testng.TestRunner.privateRun(TestRunner.java:767)
	at org.testng.TestRunner.run(TestRunner.java:617)
	at org.testng.SuiteRunner.runTest(SuiteRunner.java:335)
	at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:330)
	at org.testng.SuiteRunner.privateRun(SuiteRunner.java:291)
	at org.testng.SuiteRunner.run(SuiteRunner.java:240)
	at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
	at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
	at org.testng.TestNG.runSuitesSequentially(TestNG.java:1224)
	at org.testng.TestNG.runSuitesLocally(TestNG.java:1149)
	at org.testng.TestNG.run(TestNG.java:1057)
	at org.testng.remote.RemoteTestNG.run(RemoteTestNG.java:111)
	at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:204)
	at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:175)


===============================================
    Default test
    Tests run: 1, Failures: 1, Skips: 0
===============================================


===============================================
Default suite
Total tests run: 1, Failures: 1, Skips: 0

Link to Appium logs

[debug] [JSONWP Proxy] Proxying [POST /element] to [POST http://localhost:8100/session/6B9292D7-5B44-488B-9D68-5D8B90899294/element] with body: {“using”:“class name”,“value”:“XCUIElementTypeScrollView”} [debug] [JSONWP Proxy] Got response with status 200: {“value”:{“ELEMENT”:“22FC9416-0EB1-47CB-A800-019C566EC450”,“type”:“XCUIElementTypeScrollView”,“label”:null},“sessionId”:“6B9292D7-5B44-488B-9D68-5D8B90899294”,“status”:0} [debug] [MJSONWP] Responding to client with driver.findElement() result: {“ELEMENT”:“22FC9416-0EB1-47CB-A800-019C566EC450”,“type”:“XCUIElementTypeScrollView”,“label”:null}