org.openqa.selenium.remote.SessionNotFoundException: The FirefoxDriver cannot be used after quit() was called.
Build info: version: '2.44.0', revision: '76d78cf', time: '2014-10-23 20:02:37'
System info: host: 'cesilko-nb', ip: '127.0.1.1', os.name: 'Linux', os.arch: 'amd64', os.version: '3.13.0-24-generic', java.version: '1.8.0_40'
Driver info: driver.version: FirefoxDriver
   at org.openqa.selenium.firefox.FirefoxDriver$LazyCommandExecutor.execute(FirefoxDriver.java:359)
   at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:572)
   at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:614)
   at org.openqa.selenium.firefox.FirefoxDriver.getScreenshotAs(FirefoxDriver.java:323)
   at org.openqa.selenium.remote.server.handler.CaptureScreenshot.call(CaptureScreenshot.java:35)
   at org.openqa.selenium.remote.server.handler.CaptureScreenshot.call(CaptureScreenshot.java:1)
   at java.util.concurrent.FutureTask.run(FutureTask.java:266)
   at org.openqa.selenium.remote.server.DefaultSession$1.run(DefaultSession.java:168)
   at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
   at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
   at java.lang.Thread.run(Thread.java:745)