org.openqa.selenium.SessionNotCreatedException: A new session could not be created. (Original error: Requested a new session but one was in progress) (WARNING: The server did not provide any stacktrace information)

org.openqa.selenium.SessionNotCreatedException: A new session could not be created. (Original error: Requested a new session but one was in progress) (WARNING: The server did not provide any stacktrace information)
Command duration or timeout: 32 milliseconds
Build info: version: ‘2.53.0’, revision: ‘35ae25b’, time: ‘2016-03-15 17:00:58’
System info: host: ‘SANJEEV-YADAV’, ip: ‘192.168.25.14’, os.name: ‘Windows 10’, os.arch: ‘amd64’, os.version: ‘10.0’, java.version: ‘1.8.0_131’
Driver info: org.openqa.selenium.remote.RemoteWebDriver
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:206)
at org.openqa.selenium.remote.ErrorHandler.throwIfResponseFailed(ErrorHandler.java:158)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:678)
at org.openqa.selenium.remote.RemoteWebDriver.startSession(RemoteWebDriver.java:249)
at org.openqa.selenium.remote.RemoteWebDriver.(RemoteWebDriver.java:131)
at org.openqa.selenium.remote.RemoteWebDriver.(RemoteWebDriver.java:158)
at src_Appium.Calculator.setUp(Calculator.java:55)
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.invokeConfigurationMethod(Invoker.java:523)
at org.testng.internal.Invoker.invokeConfigurations(Invoker.java:224)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:599)
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:132)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:230)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:76)
org.openqa.selenium.UnsupportedCommandException: Invalid locator strategy: tag name (WARNING: The server did not provide any stacktrace information)
Command duration or timeout: 5 milliseconds
Build info: version: ‘2.53.0’, revision: ‘35ae25b’, time: ‘2016-03-15 17:00:58’
System info: host: ‘SANJEEV-YADAV’, ip: ‘192.168.25.14’, os.name: ‘Windows 10’, os.arch: ‘amd64’, os.version: ‘10.0’, java.version: ‘1.8.0_131’
Driver info: org.openqa.selenium.remote.RemoteWebDriver
Capabilities [{appPackage=com.android.calculator2, networkConnectionEnabled=true, warnings={}, databaseEnabled=false, version=, deviceName=0cff44e503291eee, platform=ANDROID, appActivity=com.android.calculator2.Calculator, desired={appPackage=com.android.calculator2, appActivity=com.android.calculator2.Calculator, browserName=android, platformName=Android, version=, deviceName=Emulator, platform=ANDROID}, platformVersion=6.0.1, webStorageEnabled=false, locationContextEnabled=false, browserName=android, takesScreenshot=true, javascriptEnabled=true, platformName=Android}]
Session ID: 0f0b0231-fa32-4af2-958c-d9da002f651c
*** Element info: {Using=tag name, value=EditText}
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:206)
at org.openqa.selenium.remote.ErrorHandler.throwIfResponseFailed(ErrorHandler.java:158)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:678)
at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:363)
at org.openqa.selenium.remote.RemoteWebDriver.findElementByTagName(RemoteWebDriver.java:445)
at org.openqa.selenium.By$ByTagName.findElement(By.java:334)
at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:355)
at src_Appium.Calculator.testCal(Calculator.java:75)
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:132)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:230)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:76)

I am getting this error can anyone please help me to get out from this error

kill the appium server. Unless you are on windows, you can use

killall -9 node

or if killall is not available, dig through the output of ps to identify the process.