You have a nightly version of Fx? So what does that have to do with Fx 17.0.8 ESR? This extension cannot be installed on Fx 17.0.8 ESR so I don't what you are trying to say.
You have a nightly version of Fx? So what does that have to do with Fx 17.0.8 ESR? This extension cannot be installed on Fx 17.0.8 ESR so I don't what you are trying to say.
So, did you change the version string? I don't want to do that. Years ago I did it all the time but this would be changing it to work with an earlier version of Fx not a later one. That could cause problems. At any rate, since Addons site and the author himself says it won't work on Fx 17 you should have made it clear you downloaded it from some other browser (as Fx 17 will not download it) and then changed the version string in order to force it to work on Fx 17.