I m using Selenium Webdriver to do some robottesting. Since some functions appear to only work in Firefox, I m obligated to use Firefoxdriver. Now and then, something weird happens. Starting up te driver

driver = new FirefoxDriver();
driver.get(URL);

gets firefox to startup but not to go to the specified url. The strange thing is that it works on another computer with the same preferences set in Firefox. I solved this problem once by changing to another version of firefox, but this time this doesn t do the trick for me, it did however worked for the other developers. Yes, the error started for all developers on the same time, same day... My first question is: is it a firefox problem or Webdriver problem. Second question: how is it possible that it works on other pc s?

Any help would be very appreciated Thanks

Error:

org.openqa.selenium.WebDriverException: Could not parse "".
System info: os.name:  Windows XP , os.arch:  x86 , os.version:  5.1 , java.version:  1.6.0_18 
Driver info: driver.version: firefox
    at org.openqa.selenium.firefox.Response.<init>(Response.java:53)
    at org.openqa.selenium.firefox.internal.AbstractExtensionConnection.nextResponse(AbstractExtensionConnection.java:258)
    at org.openqa.selenium.firefox.internal.AbstractExtensionConnection.readLoop(AbstractExtensionConnection.java:220)
    at org.openqa.selenium.firefox.internal.AbstractExtensionConnection.waitForResponseFor(AbstractExtensionConnection.java:213)
    at org.openqa.selenium.firefox.internal.AbstractExtensionConnection.sendMessageAndWaitForResponse(AbstractExtensionConnection.java:162)
    at org.openqa.selenium.firefox.FirefoxDriver.executeCommand(FirefoxDriver.java:329)
    at org.openqa.selenium.firefox.FirefoxDriver.sendMessage(FirefoxDriver.java:312)
    at org.openqa.selenium.firefox.FirefoxDriver.sendMessage(FirefoxDriver.java:308)
    at org.openqa.selenium.firefox.FirefoxDriver.fixId(FirefoxDriver.java:350)
    at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:130)
    at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:109)
    at be.....MMCRobotTest.login(MMCRobotTest.java:98)
    at be.....MMCRobotTestAttribute.testNewAttribute(MMCRobotTestAttribute.java:12)
    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 junit.framework.TestCase.runTest(TestCase.java:164)
    at junit.framework.TestCase.runBare(TestCase.java:130)
    at junit.framework.TestResult$1.protect(TestResult.java:106)
    at junit.framework.TestResult.runProtected(TestResult.java:124)
    at junit.framework.TestResult.run(TestResult.java:109)
    at junit.framework.TestCase.run(TestCase.java:120)
    at junit.framework.TestSuite.runTest(TestSuite.java:230)
    at junit.framework.TestSuite.run(TestSuite.java:225)
    at org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestReference.run(JUnit3TestReference.java:130)
    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: org.json.JSONException: A JSONObject text must begin with  {  at character 0
    at org.json.JSONTokener.syntaxError(JSONTokener.java:496)
    at org.json.JSONObject.<init>(JSONObject.java:180)
    at org.json.JSONObject.<init>(JSONObject.java:403)
    at org.openqa.selenium.firefox.Response.<init>(Response.java:41)
    ... 30 more