I have it working in firefox version 50.1.0, the below will allow the install of IHG and any other script that mozilla has blocked.
If you are still using the old version from the mozilla add-ons site remove it or disable it.
The developers moved it to here
Code:
http://hot-honeys.com/index.php?topic=3210.0]IHG 1.7.0.4a Released
If you want to use the outdated version from the mozilla add-on site the below will probably work on the old version also but it will not have all the updated hosts that the new version has.
first do this.
1. 1. in the address bar type about
:config
2. in the search bar enter xpinstall.signatures.required
3. change the value to false by double clicking on it.
4. restart your browser
then do this this...
source.
Code:
http://www.ghacks.net/2016/08/14/override-firefox-add-on-signing-requirement/
simply move the 2 file to the folders listed below.
you can download the files from my site if you don't want to make your own.
config.js
Move the config.js file in the Firefox installation folder.
On Windows, this is either...
C:\Program Files\Mozilla Firefox\
or
C:\Program Files (x86)\Mozilla Firefox\.
config-prefs.js
Move the file into the defaults\pref folder of the Firefox program folder.
On Windows, this is either...
C:\Program Files\Mozilla Firefox\defaults\pref
or
C:\Program Files (x86)\Mozilla Firefox\defaults\pref
Restart your browser, goto
Code:
http://hot-honeys.com/index.php?topic=3210.0]IHG 1.7.0.4a Released
and install IHG