inset extrude ad on

Im having a problem using inset extrude ad on . in 2.6 I get this message

In one 2.5 version I can not click the check box for the add on. In another version it is installed but I press I key and drag and nothing happens. I’ve used it before, I do not know what is wrong now.
Make it work in any of my builds and I will be happy.
Thank you