页面中的adobe flash插件用selenium自动化时怎么定位?报错

这个按钮在selenium自动化中定位时如下：

    WebElement selectFileButton=driver.findElement(By.cssSelector("object.swfupload"));
    selectFileButton.click();   
可运行结果在本地可以跑通，但是在另外一台机器上就定位不到这个按钮（本地运行谷歌版本为44，另一台机器上谷歌版本为47）

报错如下：

org.openqa.selenium.WebDriverException: Returned value cannot be converted to WebElement: {}
Build info: version: '2.43.0', revision: '597b76b', time: '2014-09-09 20:52:14'
System info: host: 'CVQA-PC', ip: '10.23.28.171', os.name: 'Windows 7', os.arch: 'x86', os.version: '6.1', java.version: '1.7.0_21'
Driver info: driver.version: RemoteWebDriver
 at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:359)
 at org.openqa.selenium.remote.RemoteWebDriver.findElementById(RemoteWebDriver.java:393)
 at org.openqa.selenium.By$ById.findElement(By.java:214)
 at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:344)
 at Clearvale.sanity.source.CVFilesTest.testTC004(CVFilesTest.java:171)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
 at java.lang.reflect.Method.invoke(Unknown Source)
 at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:59)
 at org.junit.internal.runners.MethodRoadie.runTestMethod(MethodRoadie.java:98)
 at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:79)
 at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:87)
 at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:77)
 at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:42)
 at org.junit.internal.runners.JUnit4ClassRunner.invokeTestMethod(JUnit4ClassRunner.java:88)
 at org.junit.internal.runners.JUnit4ClassRunner.runMethods(JUnit4ClassRunner.java:51)
 at org.junit.internal.runners.JUnit4ClassRunner$1.run(JUnit4ClassRunner.java:44)
 at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:27)
 at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:37)
 at org.junit.internal.runners.JUnit4ClassRunner.run(JUnit4ClassRunner.java:42)
 at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
 at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: java.lang.ClassCastException: com.google.common.collect.Maps$TransformedEntriesMap cannot be cast to org.openqa.selenium.WebElement
 at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:357)
 ... 26 more

求解惑！