User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.116 Safari/537.36 Steps to reproduce: In these Watir Tests: https://github.com/watir/watirspec/blob/master/option_spec.rb#L76 Interacting with options inside these optgroup tags https://github.com/watir/watirspec/blob/master/html/forms_with_input_elements.html#L27 Actual results: Option not clicked: Debugging: https://gist.github.com/titusfortner/f4410fe4b80b0f87c3c9 Expected results: Option clicked

So, the issue might not be optgroup. It looks like the issue is that the elements underneath this select list are the ones getting clicked.

I appear to have a similar issue, selecting an option simply doesn't work :( Here is the html code: <select id="id_transition" name="transition"> <option value="mclr">manual clear</option> <option value="mcls">manual close</option> <option value="cmt" selected="selected">comment</option> </select> Here is the python code trying to select option 'mclr'/'manual clear': select_action = Select(context.browser.find_element_by_xpath("//select[@id='id_transition']")) counter = 1 # try to activate element by finding correct one and clicking on it for element in select_action.options: print ('element ' + str(counter) + ': tag_name = ' + str(element.tag_name) + ', text = ' + str(element.text)) counter = counter + 1 value = str(element.get_attribute('value')) print (' value = ' + value) if value == 'mclr': print (' clicking element with value mclr') element.click() time.sleep(2) # trying to activate element by selecting by value select_action.select_by_value('mclr') time.sleep(2) # trying to activate element by selecting by index select_action.select_by_index(1) time.sleep(2) # trying to activate element by selecting by visible text select_action.select_by_visible_text('manual clear') Neither method does anything, the selector never opens and the originally selected option stays selected. I use the following software versions: OS: Ubuntu 16.04 x86_64 Firefox 47.0 as provided by Ubuntu python: 2.7.11+ as provided by ubuntu selenium: 2.53.5 as provided by pip marionette: 0.8.0 as provided by mozilla Please let me know if you need further input

I can now confirm that Forefox nightly build (50.0a1 (2016-06-18)) exhibits the same bug. BTW there may be some relationship between this bug and bugs #1255955 and #1255957