I tried the new geckodriver with marionette turned on for FF48 and selenium 3 but the test can\'t select the option in the drop down list for any element. My test works fin
I am surprised nobody experienced this issue. I guess I might have posted the question in the wrong place because I did not get any response. Anyway, this turned out to be a bug in Firefox 48. It is fixed in Firefox 51 (Nightly build).
If you are using Selenium 3 beta and Firefox 48 with geckodriver, you won't be able to interact with any drop down list using the webdriver. The issue was fixed in Firefox 51.