Version 6.5 is the latest version. If it doesn't work, this isn't the fault of the extension. If Old Layout pops up and gives you the opportunity to switch, then the extension is working! If your account can't switch, then that's Facebook preventing you from switching, not the extension. I realize that's frustrating, but that's not an issue with the extension, it's an issue with Facebook. Leaving a 1-star review for Facebook's failure is unfair to me, I think. :(