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I have been running selenium tests on a Linux Centos and it worked fine for over a year, until yesterday, when I started receiving error on my tests from Selenium:

Selenium::WebDriver::Error::UnknownError: Permission denied to access property 'nr@context' Build info: version: '2.39.0', revision: 'ff23eac', time: '2013-12-16 16:11:15' System info: host: 'selenium', ip: 'ip_address', os.name: 'Linux', os.arch: 'amd64', os.version: '2.6.32-431.3.1.el6.x86_64', java.version: '1.7.0_51' Driver info: driver.version: unknown (org.openqa.selenium.remote.ErrorHandler$UnknownServerException)

I am using Firefox as the main browser for testing and I initiate the browser like this from code:

 caps = Selenium::WebDriver::Remote::Capabilities.firefox(:firefox_profile => get_firefox_profile)

   @driver = Selenium::WebDriver.for :remote,:url => "http://#{host}:#{port}/wd/hub", :desired_capabilities => caps , :http_client => client

host is: address of my host port is 4444 on which Selenium Grid is.

What I noticed is that some of tests do pass and the once which do not pass visit different domains (though Cross Domain Testing should not be a problem for WebDriver)

Anyone experienced similar thing, or have an idea what this could be?

the Selenium Grid is started up before tests run on that machine like this:

PORTS="5555 5556 6666 6667"

java -jar SeleniumGrid/selenium-server-standalone.jar -role hub & sleep 10

for port in $PORTS do

java -jar SeleniumGrid/selenium-server-standalone.jar -role node -hub http://mymachine.com:4444/grid/register -port $port -singleWindow -firefoxProfileTemplate 'BrowserProfile/selenium' &


From tests side nothing changed yesterday. Browser, Selenium server version, code is identical as it was before it started happening.

What I noticed is that if I disable javascript when running Selenium by webdriver, test would not fail. Though tests would not work further since I disabled JS and need it for further testing in other pages.

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Hey guys, I am following a topic here: stackoverflow.com/questions/22838585/… , and it seems that the issue is happening when New Relic monitoring is enabled on a page being tested –  ibalosh Apr 4 '14 at 8:47

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