In the last 6 runs of browsertests-VisualEditor-en.wikipedia.beta.wmflabs.org-linux-firefox-sauce Jenkins job (22-27), 5 of them (22-26) failed with a random scenario raising Selenium::WebDriver::Error::StaleElementReferenceError.
Example from 26:
... 00:05:59.899 Scenario: Page Settings # features/options.feature:20 00:06:12.518 And I click in the editable part # features/step_definitions/shared_steps.rb:6 00:06:12.519 Element is no longer attached to the DOM 00:06:12.519 For documentation on this error, please visit: http://seleniumhq.org/exceptions/stale_element_reference.html 00:06:12.519 Build info: version: '2.48.0', revision: 'b7b081a', time: '2015-10-07 15:48:56' 00:06:12.519 System info: host: 'chef', ip: '127.0.1.1', os.name: 'Linux', os.arch: 'i386', os.version: '3.13.0-32-generic', java.version: '1.8.0_72' 00:06:12.519 Driver info: driver.version: unknown (org.openqa.selenium.StaleElementReferenceException) (Selenium::WebDriver::Error::StaleElementReferenceError) ...