[ubuntu] Google voice plug in after new installation - stuck

Hi,

After having problems with upgrade from 14.04 I finally decided to wipe my computer and install a clean new 16.04

That done, I am now installing the apps that I need.

I am working with reinstalled firefox web browser. Trying to make a phone call via google voice from my gmail page. I get a notice that a plug in is needed. So I hit the link.

Then I approve download:

and install:

and here the installation of the plug in gets stuck:

What do I need to do to complete the installation?