Adobe Flash in Selenium, Chrome 54.0.2840.59-1: "This plugin is not supported"
adobe, flash, google-chrome, selenium, selenium-chromedriver
Solution
Installing flash player from https://get.adobe.com/flashplayer/ works for me on mac OS, note that you will need to install this on the chrome driver browser (not the chrome browser in your system). To do this, run your selenium test that opens the chrome and from there go to that URL ^ and follow install steps. After you are done, the next time you run the test it should pick up the change and should work.
Problem
The newest update to Chrome 54.0.2840.59-1 causes selenium to not load Flash plugins. Adobe Flash Player in `chrome://plugins/` is disabled, but it's also disabled in the previous version of Chrome. This only occurs in tests when the Chromedriver is spun up, navigating to a Flash site in a normal Chrome browser shows no issues.