alert not getting detected in selenium 3.0.0-beta2 - selenium

Question

i am using selenium 3.0.0-beta2 , my alert is not getting detected with below code.
Alert alert = driver.switchTo().alert();
String Actual = alert.getText();
below is the stack trace
org.openqa.selenium.UnhandledAlertException: unexpected alert open: {Alert text : Company Already Exists}
(Session info: chrome=52.0.2743.116)
(Driver info: chromedriver=2.21.371459 (36d3d07f660ff2bc1bf28a75d1cdabed0983e7c4),platform=Windows NT 6.1 SP1 x86) (WARNING: The server did not provide any stacktrace information)
Command duration or timeout: 52 milliseconds: null
Build info: version: '2.48.2', revision: '41bccdd', time: '2015-10-09 19:55:52'
System info: host: 'tct4-PC', ip: '192.168.0.60', os.name: 'Windows 7', os.arch: 'x86', os.version: '6.1', java.version: '1.8.0_45'
Driver info: org.openqa.selenium.chrome.ChromeDriver
Capabilities [{applicationCacheEnabled=false, rotatable=false, mobileEmulationEnabled=false, chrome={chromedriverVersion=2.21.371459 (36d3d07f660ff2bc1bf28a75d1cdabed0983e7c4), userDataDir=C:\Users\tct4\AppData\Local\Temp\scoped_dir460432_24766}, takesHeapSnapshot=true, databaseEnabled=false, handlesAlerts=true, hasTouchScreen=false, version=52.0.2743.116, platform=XP, browserConnectionEnabled=false, nativeEvents=true, acceptSslCerts=true, locationContextEnabled=true, webStorageEnabled=true, browserName=chrome, takesScreenshot=true, javascriptEnabled=true, cssSelectorsEnabled=true}]
Session ID: 6f2f063385fd93923cab757a17e7364a
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:422)
at org.openqa.selenium.remote.ErrorHandler.createThrowable(ErrorHandler.java:206)
at org.openqa.selenium.remote.ErrorHandler.throwIfResponseFailed(ErrorHandler.java:164)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:647)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:670)
at org.openqa.selenium.remote.RemoteWebDriver.getScreenshotAs(RemoteWebDriver.java:325)
at com.tfleet.utilities.TakeScreenshot.takeScreenshot(TakeScreenshot.java:19)
at regression.Master.AddCompanyTest.addCompanyTest(AddCompanyTest.java:144)
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:334)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:329)
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.IDEARemoteTestNG.run(IDEARemoteTestNG.java:74)
at org.testng.RemoteTestNGStarter.main(RemoteTestNGStarter.java:121)
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 com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)

Answer 1

Info is not complete which browser you are using. If you are using with ChromeDriver then update your chrome browser and Download latest version of chromedriver from this link http://chromedriver.storage.googleapis.com/index.html. and use wait command then use it will work.
If u are using firefox then let me know.

Answer 2

Use this to handle the alert:
driver.switchTo().alert().accept();