我在使Selenium Grid演示正常工作时遇到问题。我尝试按顺序运行测试，尽管运行它们都失败了，没有启动任何浏览器。我试图用Firefox和Chrome来运行测试，并且两次都得到了相同的结果。Selenium Grid演示失败
我也跟着上的所有指令这个page（入门）和安装Java jdk1.7.0_15，apache-ant-1.8.4和selenium-grid-1.0.8（这显然是当前release，虽然我已经看到了Grid2提到？）。
我能够成功运行命令
ant sanity-check
，并有电网编译。然后我移动到demo page：
ant launch-hub
，我能够在本地主机，查看轮毂：4444 /控制台
ant launch-remote-control
，我看到可用的浏览器出现在我的枢纽。
当运行
ant run-demo-in-sequence
可用遥控器现在显示为在轮毂的主动控制和运行的测试，但所有4失败。 Firefox无法打开，也没有看到任何新的浏览器打开。
当我浏览到target/reports/index.html页面（位于电网目录），我能够找到下面的错误，这是每一个失败的试验一样：
java.lang.RuntimeException: Could not start Selenium session: ERROR: Could not retrieve a new session at com.thoughtworks.selenium.DefaultSelenium.start(DefaultSelenium.java:89) at com.thoughtworks.selenium.grid.tools.ThreadSafeSeleniumSessionStorage.startSeleniumSession(ThreadSafeSeleniumSessionStorage.java:26) at com.thoughtworks.selenium.grid.demo.WebTestForASingleBrowser.domme(WebTestForASingleBrowser.java:51) at org.apache.tools.ant.taskdefs.ExecuteJava.run(ExecuteJava.java:217) at org.apache.tools.ant.taskdefs.ExecuteJava.execute(ExecuteJava.java:152) at org.apache.tools.ant.taskdefs.Java.run(Java.java:771) at org.apache.tools.ant.taskdefs.Java.executeJava(Java.java:221) at org.apache.tools.ant.taskdefs.Java.executeJava(Java.java:135) at org.apache.tools.ant.taskdefs.Java.execute(Java.java:108) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.Target.execute(Target.java:392) at org.apache.tools.ant.Target.performTasks(Target.java:413) at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1399) at org.apache.tools.ant.Project.executeTarget(Project.java:1368) at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41) at org.apache.tools.ant.Project.executeTargets(Project.java:1251) at org.apache.tools.ant.Main.runBuild(Main.java:811) at org.apache.tools.ant.Main.startAnt(Main.java:217) at org.apache.tools.ant.launch.Launcher.run(Launcher.java:280) at org.apache.tools.ant.launch.Launcher.main(Launcher.java:109) Caused by: com.thoughtworks.selenium.SeleniumException: ERROR: Could not retrieve a new session at com.thoughtworks.selenium.HttpCommandProcessor.throwAssertionFailureExceptionOrError(HttpCommandProcessor.java:97) at com.thoughtworks.selenium.HttpCommandProcessor.doCommand(HttpCommandProcessor.java:91) at com.thoughtworks.selenium.HttpCommandProcessor.getString(HttpCommandProcessor.java:262) at com.thoughtworks.selenium.HttpCommandProcessor.start(HttpCommandProcessor.java:223) at com.thoughtworks.selenium.DefaultSelenium.start(DefaultSelenium.java:81) ... 50 more ... Removed 29 stack frames
，而在输出其中，我公司推出的测试CMD窗口原文：
run-demo-in-sequence:
[java] [Parser] Running:
[java] Selenium Grid Demo In Sequence
[java]
[java]
[java] ===============================================
[java] Selenium Grid Demo In Sequence
[java] Total tests run: 4, Failures: 4, Skips: 0
[java] ===============================================
[java]
BUILD FAILED
C:\Program Files\selenium-grid-1.0.8-bin\selenium-grid-1.0.8\build.xml:116: Java
returned: 1
Total time: 1 minute 33 seconds
我Firefox版本是18.0.2。另外，我也看到了Selenium-standalone ..在其他类似的问题中提到过，但在我正在遵循的教程的任何地方都没有提及，我需要吗？
任何人都可以帮助演示工作，并解释我要去哪里错了吗？