Posted 28 December 2015 - 11:08 AM
See the Firefox help page entitled, Add-On Signing in Firefox, paying particular attention to the section, Override add-on signing (advanced users).
I would first check to see if HP has issued a signed version of this add-on before taking the route of editing the Firefox configuration file. If they have not then this is your only choice if you wish that add-on to be able to run until a signed version is released. If you have to tweak the Firefox configuration file you should tweak it back if a signed version is released. These protections have come into existence for good reason.
Edited by britechguy, 28 December 2015 - 11:09 AM.
Brian AKA Bri the Tech Guy (website in my user profile) - Windows 10 Home, 64-Bit, Version 1803, Build 17134
In a modern society where everyone thinks their opinion deserves to be heard nothing annoys me more than individuals who mistake their personal preferences for fact.
~ Commenter TheCruyffGurn on the The Guardian website, 8/13/2014