KDecker KDecker - 2 months ago 24
Java Question

Selenium WebDriver upgrade results in UnreachableBrowserException

I recently found that my Selenium Java libraries were not working. Version 2.48.2 would open a Firefox window and then "stall" with no error within Netbeans nor Firefox itself before returning from

new FirefoxDriver()
. I figured that this version of Selenium might be broken so I found the latest Java libraries (Version 2.53.1) and have been trying to get them to work.

My issue now is almost the same but with two errors. The first is thrown by Netbeans when trying to execute
new FirefoxDriver()

Exception in thread "AWT-EventQueue-0" org.openqa.selenium.remote.UnreachableBrowserException: Could not start a new session. Possible causes are invalid address of the remote server or browser start-up failure.
Build info: version: '2.53.1', revision: 'a36b8b1', time: '2016-06-30 17:32:46'
System info: host: 'MrComputer', ip: '', os.name: 'Windows 7', os.arch: 'amd64', os.version: '6.1', java.version: '1.8.0_65'
Driver info: driver.version: FirefoxDriver
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:665)

The second is from Firefox itself. The window opens but instantly encounters the error.

Problem signature:
Problem Event Name: APPCRASH
Application Name: firefox.exe
Application Version:

The code I am using is quite simple. Just the line

WebDriver driver = new FirefoxDriver();

I am by no means an extremely knowledgeable Selenium user so I am not sure what other information I could provide that might be of help.

EDIT: It seems that my Firefox version was not high enough to use the 2.53.1 Selenium libraries. My version of
needed to be at least

Prior to this, version 2.53.0 did need to make use of the
as per this SO answer.

Unfortunately Selenium WebDriver 2.53.0 is not compatible with Firefox
47.0. The WebDriver component which handles Firefox browsers (FirefoxDriver) will be discontinued. As of version 3.0, Selenium
WebDriver will have MarionetteDriver as the default running
implementation for Firefox tests.



Selenium WebDriver 2.53.1 has been released on 30th June 2016.
FirefoxDriver is working again with Firefox 47.0.1 as browser.


For Selenium 2.53.1 the Firefox version needs to be at least 47.0.1. Updating my Firefox did the trick.

EDIT: It also seems that version 47.+ was not released to the Ubuntu archives for a few weeks after the Windows version.