Firefox 42.0 and Norton Toolbar a no-go (11/3/15)

I was hoping that the patch delivered this a.m. would be the 'fix'.  In Firefox Add-ons, I found what I think is a new Norton Toolbar.  However, there was a problem there.  See PDF image.  Firefox didn't install the add-on, but says proceed with caution.  How do I do that?  There's no information that states how that is done.  Norton and Firefox are fully updated.  Art is sad.