Unable to run tests in parallel androidx.test.uiautomator.StaleObjectException

The problem

I am trying to run the tests in parallel, the app launches and performs some actions but for a specific screen, the test fail in 1 device and continues correctly in the 2nd device, i get the following error:

androidx.test.uiautomator.StaleObjectException

Weird thing here is that if i change the TestNG tag parallel=tests by parallel=class or methods or anyother the execution does not fail, but the execution starts and finishes in 1 device and then it starts in the 2nd device, but i would like to start the execution parallelly in the two devices, as i said it only fails while trying to click 1 specific item on the screen Thanks in advanced!

Environment

• Appium version (or git revision) that exhibits the issue: 1.15.1
• Last Appium version that did not exhibit the issue (if applicable): 1.15.1
• Desktop OS/version used to run Appium: macos mojave 10.14.5
• Node.js version (unless using Appium.app|exe): 12.11.1
• Npm or Yarn package manager: 6.12.0
• Mobile platform/version under test: ANDROID
• Real device or emulator/simulator: Xiaomi REdmi s2, Lg V20, Galaxy S9

Details

If necessary, describe the problem you have been experiencing in more detail.

Link to Appium logs

org.openqa.selenium.StaleElementReferenceException: androidx.test.uiautomator.StaleObjectException For documentation on this error, please visit: https://www.seleniumhq.org/exceptions/stale_element_reference.html Build info: version: ‘3.141.59’, revision: ‘e82be7d358’, time: ‘2018-11-14T08:17:03’ System info: host: ‘sprout24.local’, ip: ‘fe80:0:0:0:1064:76eb:12e1:5b9e%en0’, os.name: ‘Mac OS X’, os.arch: ‘x86_64’, os.version: ‘10.14.5’, java.version: ‘1.8.0_162’ Driver info: io.appium.java_client.android.AndroidDriver Capabilities {appActivity: com.xxxx.android.activ…, appPackage: com.xxxx.android, automationName: uiautomator2, clearSystemFiles: true, databaseEnabled: false, desired: {appActivity: com.xxxx.android.activ…, appPackage: com.xxxx.android, automationName: uiautomator2, clearSystemFiles: true, deviceName: LGH910532e4945, deviceReadyTimeout: 260, fullReset: false, newCommandTimeout: 6000, noReset: true, platformName: android, platformVersion: 7, skipDeviceInitialization: true, systemPort: 4733, udid: LGH910532e4945, uiautomator2ServerLaunchTimeout: 20000}, deviceApiLevel: 24, deviceManufacturer: LGE, deviceModel: LG-H910, deviceName: LGH910532e4945, deviceReadyTimeout: 260, deviceScreenDensity: 640, deviceScreenSize: 1440x2560, deviceUDID: LGH910532e4945, fullReset: false, javascriptEnabled: true, locationContextEnabled: false, networkConnectionEnabled: true, newCommandTimeout: 6000, noReset: true, pixelRatio: 4, platform: LINUX, platformName: Android, platformVersion: 7.0, skipDeviceInitialization: true, statBarHeight: 96, systemPort: 4733, takesScreenshot: true, udid: LGH910532e4945, uiautomator2ServerLaunchTimeout: 20000, viewportRect: {height: 2296, left: 0, top: 96, width: 1440}, warnings: {}, webStorageEnabled: false} Session ID: e8ecd20f-032a-44a2-ad62-65b909ce895f 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.http.W3CHttpResponseCodec.createException(W3CHttpResponseCodec.java:187) at org.openqa.selenium.remote.http.W3CHttpResponseCodec.decode(W3CHttpResponseCodec.java:122) at org.openqa.selenium.remote.http.W3CHttpResponseCodec.decode(W3CHttpResponseCodec.java:49) at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:158) at io.appium.java_client.remote.AppiumCommandExecutor.execute(AppiumCommandExecutor.java:239) at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:552) at io.appium.java_client.DefaultGenericMobileDriver.execute(DefaultGenericMobileDriver.java:41) 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.RemoteWebElement.execute(RemoteWebElement.java:285) at io.appium.java_client.DefaultGenericMobileElement.execute(DefaultGenericMobileElement.java:45) at io.appium.java_client.MobileElement.execute(MobileElement.java:1) at io.appium.java_client.android.AndroidElement.execute(AndroidElement.java:1) at org.openqa.selenium.remote.RemoteWebElement.click(RemoteWebElement.java:84) at PageObjects.HomeScreenInsta.clickFollowersBtn(HomeScreenInsta.java:56) at TestCases.GetAllUsers.getAllUserAccounts(GetAllUsers.java:71) 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:133) at org.testng.internal.TestInvoker.invokeMethod(TestInvoker.java:584) at org.testng.internal.TestInvoker.invokeTestMethod(TestInvoker.java:172) at org.testng.internal.MethodRunner.runInSequence(MethodRunner.java:46) at org.testng.internal.TestInvoker$MethodInvocationAgent.invoke(TestInvoker.java:804) at org.testng.internal.TestInvoker.invokeTestMethods(TestInvoker.java:145) at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:146) at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:128) at java.util.ArrayList.forEach(ArrayList.java:1257) at org.testng.TestRunner.privateRun(TestRunner.java:770) at org.testng.TestRunner.run(TestRunner.java:591) at org.testng.SuiteRunner.runTest(SuiteRunner.java:402) at org.testng.SuiteRunner.access$000(SuiteRunner.java:41) at org.testng.SuiteRunner$SuiteWorker.run(SuiteRunner.java:443) at org.testng.internal.thread.ThreadUtil.lambda$execute$0(ThreadUtil.java:67) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748)

This is my testng file

  <?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE suite SYSTEM "https://testng.org/testng-1.0.dtd" >
<suite name="Smoke" thread-count="2" parallel="tests">
    <listeners>
       <listener class-name="resources.Listeners"/>
       <!-- <listener class-name="resources.ExtentReporterNG" />-->
    </listeners>
<test name="LG_V20"  >
        <parameter name="deviceName" value="LGH910532e4945"></parameter>
        <parameter name="platformVersion" value="7"></parameter>
        <parameter name="port" value="4733"></parameter>
        <classes>
            <class name="TestCases.GetAllUsers">
              </class>
        </classes>
    </test>
    <test name="RedmiS2" >
        <parameter name="deviceName" value="ad789708"></parameter>
        <parameter name="platformVersion" value="9"></parameter>
        <parameter name="port" value="4734"></parameter>
        <classes>
            <class name="TestCases.GetAllUsers">
            </class>
        </classes>
    </test>
</suite>

[KazuCocoa]

Did you check http://appium.io/docs/en/advanced-concepts/parallel-tests/ ?

[hadrianjmnz90]

I found the solution, public AndroidDriver<MobileElement> driver; was static, so i only removed the declaration, but anyways it was good to change the systemport and the appium port. Thanks!