Selenium can not interact with the Flash Object. You will need to use FlashSelenium, very old project. It might work,
You can use FlashSelenium, which is quite old but seems to work:
I see the last commit done was in 2011
You can even try using Sikuli, Adobe's Genine or Ranorex's library
If you are closely working with developers, you can ask them to expose few functions via JavaScript and further you can use JavaScript to interact with the Flash Object.
Hope that helps!